Pressure Monitoring Flow Monitoring Pressure Switches, Pressure Monitors, Pressure Limiters Flow Monitors, Airflow Monitors H f Steam Hot water Fuel gases Liquid fuels (e. g. heating oil) Pressure vessels (e. g. for liquefied gas) Other Media (liquid and gaseous) TÜV DVGW
Pressure Switches Technical features Die-cast aluminium housing IP 54 oder IP 65 Also explosion-proof Wall mounting or directly on pressure line Switching Element (Micro switch) Set adjustment (also sealable) Setpoint spindle locking Plug or terminal connection Stainless steel sensor housing Stainless steel pressure bellows with internal stop Pressure connection G 1/2 external thread + G 1/4 internal thread Centering pin (for G 1/2HH connection with sealing washer)
Contents Series Page Terms Pressure data 4 Pressure units 4 Switching differential 5 Direction of action 5 Technical Informations Switching housings and switching kinematics 6 Sensor elements 6 Pressure monitoring in explosion endangered areas 7 9 Selection of a pressure switch 10 General technical description 11 The most important technical data 12 Optional functions, switching elements, connection diagrams 13 15 Adjustment instructions 16 Interlock of switching status (Pressure Limiter) 17 Type code 18 Pressure, negative pressure and differential pressure switches Pressure switches and Pressure monitors for overpressure DCM 19 (for non aggressive liquid and gaseous media) Negative Pressure Switch (Vacuum switch) VCM 20 Pressure switches with sensor system in stainless steel version DNM 21 Pressure- and negative pressure switches with high grade steel sensor DNS 22 Differential pressure monitors DDC 23 Two-stage pressure switches (with two micro switches) S2 24 27 Pressure monitoring in thermal engineering systems Pressure limiters of special contraction Explanations 28 31 Standards Directives Component tests 32 Selection of pressure monitors / limiters 33 34 Pressure monitors / limiters for maximum pressure monitoring DA 35 Pressure monitors for steam, hot water, burnable gases, liquid fuels DWR 36 Pressure limiters with manual reset DWR-B 37 Pressure monitors for burnable gases DGM 38 Maximum pressure limiters for liquid gas systems FD 39 Pressure monitors, pressure limiters for safety-relevant application DBS 40 42 Dimensional drawings 43 44 Pressure switches for ventilation and air-conditioning Accessories Differential pressure switch for air DPS 45 Pressure and differential pressure switches for neutral gases HCD 46 Isolating switching amplifier for intrinsically safe control circuits EX 011 47 Isolating switching amplifier in safety technology EX 041 48 Pressure mediators / separating membranes FV 49 Siphons, connection nipples, pressure surge reducer 50 Shut-off valves, valve combinations 51 Flow monitoring, air flow monitoring Flow monitoring in liquids and gases SWW 52 Airflow monitoring for cabinet installation SWL 53 Quotation texts for all products 54 55 3
INFO Terms Overpressure (+) Negative pressure ( ) Atmospheric pressure Fluctuations of the atmospheric pressure absolute 0 Pressure data Overpressure Pressure above the relevant atmospheric pressure. The reference point is the atmospheric pressure. Negative pressure Pressure below the relevant atmospheric pressure. The reference point is the atmospheric pressure. Differential pressure Pressure difference between 2 pressure measuring points. Relative pressure Overpressure or negative pressure relative to the relevant atmospheric pressure. The pressure data in all FEMA documents must be understood as relative pressure. Pressure (bar) Permissible operating pressure 20 bar Bursting pressure > 100 bar Therefore it is always the pressure difference in relation to the relevant atmospheric pressure. Overpressure receives a positive sign, negative pressure a negative sign. Absolute pressure Pressure below the absolute vaccum. Operating pressure (maximum permissible pressure) The maximum operating pressure is understood as the upper limit at which the function, the switching safety and the tightness are in no way impaired (see type overview for values). Bursting pressure (test pressure) For the component-tested types, it is certified by a pressure test confirmed by the TÜV that the bursting pressure reaches at least the values named in the type overview. It is true that the measuring bellows are permanently deformed in the pressure tests, but there has been no leakage or bursting of the pressure-bearing parts. The bursting pressure is as a rule a multiple of the permissible operating pressure. Setting range Pressure range in which the switching point can be set by the setpoint spindle. Pressure units Units bar mbar Pa kpa MPa (psi) lb / m 2 1bar 1 1000 10 5 100 0.1 14.5 1mbar 0.001 1 100 0.1 10 4 0.0145 1Pa 10 5 0.01 1 0.001 10 6 1.45 x 10 4 Setting range 0.5... 6 bar 1kPa 0.01 10 1000 1 0.001 0.145 1MPa 10 10 4 10 6 1000 1 145 The pressures are stated in bar or mbar in all FEMA documents. Pressure data for a pressure switch Example DWR 625: Setting range: 0.5 6 bar Permissible operating pressure: 20 bar Bursting pressure: > 100 bar Important Note: All pressure data are overpressures or negative pressures compared with atmospheric pressure. Overpressures have a positive sign, negative pressure a negative sign. 4
INFO Terms Maximum pressure monitoring RSP = SP xd Pressure Minimum pressure monitoring RSP = SP+xd Pressure SP = Switching point RSP = Switching-back point xd = Switching differential (hysteresis) SP = Switching point RSP = Switching-back point xd = Switching differential (hysteresis) Switching differential The switching differential (hysteresis) is the pressure difference between the switching point (SP) and the switching-back point (RSP) of a pressure switch. The switching differential has tolerances resulting due to tolerances in the microswitches, springs and pressure bellows. The data in the type overviews are therefore always mean values. In the case of limiter functions, the switching differential is completely without importance since only the switching point at which the cut-off takes place is of interest and not the switching-back point. In the case of a controller function, i.e. for pressure switches, which are used for switching a burner, a pump etc. on and off, choose a pressure switch with adjustable switching differential.the switching frequency of the burner or of the pump can be influenced by changing the switching differential. Adjustable switching differential In the case of pressure switches with adjustable switching differential, the hysteresis can be set within the prescribed limits. The switching point (SP) and switching-back point (RSP) can be defined exactly. When adjusting the pressure switch, observe the position of the switching differential or the type of factory adjustment. Some pressure switches are adjusted for falling pressure (e.g. DCM series), i.e. the switchover on falling pressure takes place at the scale value, the switching differential lies above this, switching-back occurs at the scale value + switching differential. If the pressure is adjusted for rising, the switch-over takes place at the scale value, switching back at the scale value switching differential (see direction of action). The type of adjustment is stated in the data sheets. Direction of action In principle every pressure switch can be used both for maximum pressure and for minimum pressure monitoring. Pressure limiters the direction of action of which (max. or min.) is mandatory are an exception to this. It must only be noted that the scale reading can deviate by the switching differential. Refer to the example further below: scale value is 2.8 bar. Maximum pressure monitoring Under rising pressure,switch-over occurs on reaching the set switching pressure (SP).The switching-back point (RSP) is lower by the switching differential. Overpressure (+) Negative pressure ( ) Pressure (e. g. 0.6 bar) Atmospheric pressure absolute 0 (e. g. 0.55 bar) Pump on (scale value) SP = Switching point RSP = Switching-back point Pump off Minimum pressure monitoring Under falling pressure, switch-over occurs on reaching the set switching pressure (SP). The switching-back point (RSP) is higher by the switching differential. Direction of action in the negative pressure range The definition of the direction of action in the negative pressure range is especially important. Rising here does not mean rising vacuum, but rising pressure (viewed from absolute 0 ). Falling pressure means rising vacuum. Example: Vacuum switch, set to 0.6 bar falling means: Under falling pressure (rising vacuum), switch-over occurs at 0.6 bar (SP). The switchingback point is higher by the switching differential (e.g. at 0.55 bar). Data for the adjustment of a pressure switch To define the switching point of a pressure switch exactly, it is always necessary to determine the direction of action as well apart from the pressure data. The statement rising means that switching over is triggered at the determined setting value, if the pressure rises.the switching-back point is then lower by the switching differential. The statement falling must be understood analogously. Important data for the adjustment of a pressure switch: Apart from the switching point, also state the direction of action (falling or rising). Example of the selection of a pressure switch: A pump has to be switched on at 2.8 bar and switched off again at 4.2 bar. Selected type: DCMV 6 according to data sheet DCM. Adjustment: Scale pointer to 2.8 bar (lower switching point). Switching differential to 1.4 bar (adjust according to pressure gauge). Cut-off point: 2.8 bar + 1.4 bar = 4.2 bar. 5
Switch housings and switching kinematics The switch housings consist of high quality and seawater-resistant aluminium die castings. 4 versions are available: Normal version Housing 200 Housing 300 Housing 500 Housing 700 Plug connection according to DIN 43 650, Pg 11 Terminal connection, cable entry Pg 11 EEx-i equipment for type of protection against explosion EEx-ia EEx-d version, type of protection against explosion EEx de IIC T6 Type of protection IP 54 Type of protection IP 65 Type of protection IP 65 Type of protection IP 65 Microswitch, single-pole switch-over, 8 A, 250 V AC Microswitch, single-pole switch-over, 8 A, 250 V AC Terminal connection and cable entry blue Terminal connection, cable entry Pg 11 Two-stage versions and special equipment possible Two-stage versions and special equipment possible Microswitch, single-pole switch-over Microswitch, single-pole switch-over, 3 A, 250 V AC Switching point and switching differential can be set from the outside Switching point and switching differential can be set after removing the cover Switching point can be set after removing the cover Switching point can be set after removing the cover External isolating switching amplifier required Sensor elements for pressure switches All sensors can be combined optionally with the above switching mechanisms Sensor made of copper Sensor made of steel/stainless steel Sensor made of high quality for pressures up to 1.6 bar for pressures starting from 1 bar stainless steel (recognizable by the groove) Pressure sensor made of Diffential pressure sensor made Differential pressure sensor made steel/stainless steel for high of steel/stainless steel of aluminium with Perbunan pressures diaphragm The figures show only a selection of available sensors. 6
INFO General information on explosion protection Basic principle The basic principle of explosion protection consists in preventing the simultaneous occurrence of: a) Combustible substances (gas, vapour, mist or dust) in quantity threatening danger b) Air (or oxygen) c) Ignition sources The constant oroccasional occurrence ofexplosible mixtures according to a and b frequently cannot be avoided, therefore care must be taken in the operation of electrical systems that no ignition sources can arise. For this purpose there are the following European standards, which are resolved by the technical committee CENELEC and are recognized in all EU countries. x General provisions EN 50 014 x Oil immersion o EN 50 015 x Pressurized apparatus p EN 50 016 x Powder filling q EN 50 017 x Flameproof enclosure d EN 50 018 x Increased safety e EN 50 019 x Intrinsic safety i EN 50 020 x Encapsulation m EN 50 028 The directives relevant for the FEMA products are apart from the General provisions EN 50 014 the Flameproof enclosure d and the Intrinsic safety i. Flameproof enclosure d Switching elements and other electrical functional units which can ignite an explosible mixture are enclosed in a housing which withstands in the interior the explosion pressure in an explosion and prevents transmission to the surrounding atmosphere. EEx-d Intrinsic safety i The equipment used in the explosion endangered area contains only intrinsically safe circuits. A circuit is intrinsically safe if the energy quantity is so small that no spark and no thermal effect can arise. EEx-i Zone classification Zone classification for areas, which are explosion endangered by combustible gases, vapours or mist: Explosion endangered rooms are classified into zones according to the probability of the occurrence of a dangerous explosible atmosphere. In the assessment of the explosion risk, i. e. in determining explosion endangered areas, the Directives for avoiding the dangers due to explosible atmosphere with collection of examples (ExRL) of the Chemical Employers Liability Insurance Association must be taken into account.if it is a question of special cases,or if doubts exist concerning the determination of explosion endangered areas, the supervisory authorities (Trade Supervisory Office, possibly with cooperation of the Employers Liability Insurance Association or the Technical Control Association) decide. In Zones 0 and 1 only electrical equipment for which a design test certificate of a recognized testing agency exists may be used. In Zone 0, however, only those which are expressly approved for this. In Zone 2 the equipment approved for use in Zones 0 and 1 may also be used. Also electrical equipment which corresponds to the requirements in VDE 0165/9.83, Section6.3canbeusedinZone2. Dangerous, explosible atmosphere present Ex 67 17.03.98/01 constant or long term Zone 0 comprises areas in which dangerous explosible atmosphere is present constantly or long term. This includes as a rule only the interior of containers or the interior of apparatus (evaporators, reaction vessels etc.) if the conditions of the definition of Zone 0 are fulfilled. (according to ExRL) 7
INFO General information on explosion protection occasionally infrequently and short term Zone 1 comprises areas in which it can be expected that dangerous explosible atmosphere occurs occasionally. This can include the following: x The closer vicinity of Zone 0 x The closer vicinity of feed openings x The closer area around filling and emptying equipment x The closer area around fragile apparatus or lines made of glass, ceramic and the same x The closer area around not sufficiently sealing glands, e. g. on pumps and slide valves x The interior of apparatus such as evaporators, reaction vessels (according to ExRL) Zone 2 comprises areas in which it can be expected that dangerous explosible atmosphere occurs only infrequently and then also only short term. This can include the following: x Areas surrounding Zones 0 or 1 x Areas around flange connections with flat gaskets of customary construction in pipelines in enclosed rooms Explosion group The requirements on the explosion protected equipment depend upon the gases and/or vapours present at the equipment. This influences the required gap dimensions for the flameproof enclosure and in the case of intrinsically safe circuits the maximum permissible current and voltage values.gases and vapours are therefore classified according to different explosion groups. The dangerous nature of the gases increases from explosion group IIA to IIC, whereby equipment which is approved for IIC can also be used for all other explosion groups. Temperature class The maximum surface temperature of equipment must always be less than the ignition temperature of the gas or vapour mixture. The temperature class is therefore a measure of the maximum surface temperature of a piece of equipment. Temperature class Ignition temperature hc Maximum surface temperature hc T1 > 450 450 T2 > 300 300 T3 > 200 200 T4 > 135 135 T5 > 100 100 T6 > 85 85 Identification of explosion protected electrical equipment In addition to the normal data (manufacturer, type, serial number, electrical data) the data concerning the explosion protection must be included in the identification. The following identification is specified in the European standards based on the IEC recommendations: Ex 67 17.03.98/01 Example: EEx d IIC T 6 Identification for equipment which is certified by an EU test agency Symbol for equipment which is built according to European standards Identification of the ignition protection type used Explosion group Temperature class In addition the test agency and the number of the conformity certificate must be stated. 8
INFO Pressure monitoring in explosion-endangered areas Pressure switches with special equipment can also be used in the Ex area Zone 1 and 2. Ex area Ex area Ex area The following alternatives are possible: 1. Pressure switch with pressure-proof encapsulated switching device, degree of protection EEx de IIC T6 The pressure switch in pressure-proof encapsulation can be used directly in the Ex area (Zone 1 and 2). Maximum switching voltage, switching capacity and ambient temperature must be taken into account and the rules for the installation in the Ex area must be observed. All pressure switches can be equipped with Ex switching mechanisms. Special circuits as well as versions with adjustable switching differences are not possible. 2. Pressure switches in EEx-i-version All pressure switch in normal version can be used in the Ex area Zone 1 and 2 if they are incorporated in an intrinsically safe circuit. In principle the intrinsic safety is based on that fact that the control circuit run in the Ex area carries only a small amount of energy which is not able to generate ignitable sparks. Isolating switching amplifiers, e. g. Type Ex 011 or Ex 041 must be tested by the PTB and approved for Ex-installations. Isolating switching amplifiers must in any event installed outside the Ex zone. Pressure switches which are intended for EEx-ia installations can be equipped with blue terminals and cable entries. Because of the low voltages and currents which are carried by the contacts of the microswitch, gold plated contacts are recommended (additional function ZF 513). 3. Pressure switches with microswitch and series resistor for wire breakage and short circuit monitoring A combination of pressure switch with mechanical microswitch connected with a 1.5 k series resistor and a 10 k parallel resistor and an isolating switching amplifier in safety technology (Type Ex 041) can also be used for Ex zone 1 and 2 (degree of protection EEx-ia). The isolating switching amplifier in safety technology generates an intrinsically safe control circuit and simultaneously monitors the supply line between the isolating switching amplifier and pressure switch for short circuit and line break. Please refer to the chapter on pressure switches in safety technology and data sheet Ex 041. Pressure monitoring in Ex areas Zone 1 and 2 Ex-D... D...-513 + Ex 011 DWR...-576 + Ex 041 Flameproof enclosed Intrinsically safe Instrinsically safe, line break and short circuit monitoring Ignition protection type: Ignition protection type: Ignition protection type: EEx de IIC T6 EEx ia EEx ia PTB approval for the complete PTB approval for isolation PTB approval for isolation switchgear Switching capacity switching amplifiers Ex 011. switching amplifiers Ex 041. at 230 V / 3 A. Pressure switches with gold- Pressure switches with safety plated contacts, blue terminals sensor, forced opening microand blue cable entries. switch, gold-plated contacts, blue terminals and blue cable entries. The pressure switch can be The isolation switching The isolation switching installed inside the Ex zone. amplifier must be installed amplifier must be installed outside the Ex zone. outside the Ex zone. 9
INFO 10 criteria to observe in the selection of a pressure monitor / pressure limiter C H E C K L I S T 1 Medium Steam, hot water, fuel gases, air, flue gases, liquefied gas, liquid fuels, other media 1a Sensor material Stainless steel, non-ferrous metals, plastics (e. g. Perbunan). Are all sensor materials resistant to the medium? Oil- and grease-free for oxygen? 2 Type approval Is a type approval (TÜV, DVGW, PTB, etc.) required for the intended application? 3 Function Monitor, limiter (with internal or external interlock). Pressure limiter in safety engineering? 4 Direction 5 Setting Should the maximum pressure or the minimum pressure be of action monitored? Does the pressure switch have a controller function (e. g. pump on and off)? range Take the wanted setting range from the type overviews. 6 Switching diff. Only for controllers / monitors The adjustable switching differential is important only for pressure switches with controller function. The switching differential (hysteresis) has no significance for limiter functions. 7 Max. permissible operating pressure The maximum permissible operating pressure named in the tables must be the same as or greater than the maximum system pressure. 8 Ambient conditions Medium temperature / ambient temperature / type of protection / humidity / Ex zone / Outdoor installation protective measures 9 Design / Size Pressure connection Size, installation position, installation possibility, pressure connection with gasket. 10 Electric data Switching capacity Switching element / change-over contact / normally closed contact / normally open contact / switching capacity / interlocking / gold contacts / contactless signal transmission. This list of criteria does not claim to be complete. However, all items must be checked. The stated sequence is expedient but not mandatory. 10
INFO Pressure switches General description Mode of operation The pressure applied in the sensor housing (1) acts on the measuring bellows (2). Pressure changes lead to movements of the measuring bellows (2) which are transferred through a pressure pin (4) to the switching rocker (5). The switching rocker is supported on hardened pivot points (6). As the pressure increases the switching rocker (5) moves upwards and operates the microswitch (7).The spring (8), the initial stress of which can be changed by the setting screw (9) (switching point setting), acts as opposing force. The traveling nut (10) is moved by turning the setpoint spindle and the initial stress of the spring (8) is changed. The screw (11) serves for the internal adjustment of the microswitch. The counterpressure spring (12) ensures stable switching behaviour, even for low setting values. 1 = pressure connection 2 = measuring bellows 3 = sensor housing 4 = pressure pin 5 = switching rocker 6 = pivot points 7 = microswitch or other switching elements 8 = setpoint spring 9 = setting spindle (switching point setting) 10 = traveling nut (switching point indicator) 11 = adjusting screw for microswitch 12 = counterpressure spring Pressure sensors With few exceptions in the low pressure range, all pressures sensors are equipped with measuring bellows, partly made of a copper alloy but mostly in high stainless steel quality. In comparison with the permissible values, the measuring bellows are subject to low loads and move only slightly. This results in long service life with low switching point drift and high overpressure safety. The movement of the measuring bellows is also restricted by an internal stop so that the forces resulting from the overpressure can not be transmitted to the switching mechanism. The parts of the sensor in contact with the medium are welded together without additional materials and the sensors contain no seals. Cu bellows which are used for low pressure ranges are soldered to the sensor housing. The sensor housing and all parts in the unit in contact with the medium can also be manufactured completely in stainless steel 1.4571 (series DNS).The individual data sheets contain exact data on materials. Pressure connection The pressure connection is designed in accordance with DIN 16288 for all pressure switches (pressure gauge connection G 1/2A). They can also be connected optionally to the internal thread G 1/4 in accordance with ISO 228 Part 1. The centering pin must then be removed. Max. screw-down depth on the internal thread G 1/4 = 9 mm. Centering pin When connected to the external thread G 1/2 with seal in the thread (i. e. without the sealing washer customary in the pressure gauge connection), the centering pin must be removed. Differential pressure switches have two pressure connections (max. and min.) and must be connected to one internal thread G 1/4 each. 11
The most important technical data Valid for all pressure switch with microswitches of the DCM,VCM, DNM, DNS, DDC series.the technical data of the component tested units deviate partly slightly. (Please refer to type sheet) Normal version Plug connection Terminal connection -version... 200... 300...700 Switching device Aluminium diecast GD AI Si 12 Aluminium diecast GD AI Si 12 Pressure connection G 1 /2 external thread (pressure gauge connection) and G 1 /4 internal thread. Internal thread G 1 /4 at differential pressure switches DDCM. Switching function and Floating change-over contact. Floating change-over contact. connection drawing With rising pressure switching over With rising pressure switching over (applies only for version single-pole from 3 1 to 3 2 single-pole from 3 1 to 3 2 with microswitch) Switching capacity (applies only for version with microswitch) 8 A at 250 V AC 3 A at 250 V AC 5 A at 250 V AC inductive 2 A at 250 V AC inductive 8Aat24VDC 3Aat24VDC 0.3 A at 250 V DC 0.03 A at 250 V DC inductive Fitting position arbitrary preferably vertical vertical see data sheet Degree of protection (in vertical position) IP 54 Terminal connection IP 65 Ex degree of protection EEx de IIC T6 tested according to EN 50014/50018/50019 (CENELEC) PTB approval Ex 90.C.1059 Electrical connection Plug connection (200 series) or Terminal connection Terminal connection (300 series) Cable entry Pg 11 Pg 11 Ambient temperature See data sheets 15 to +60 hc IP 65 Switching point Adjustable on the spindle. Adjustable on the spindle after the In switching mechanism 300 the terminal box lid is removed. terminal box lid must be removed. Switching difference Adjustable or not adjustable Not adjustable (see type overview) Medium temperature Max. 70 hc, briefly 85 hc Max. 60 hc Highermedium temperatures are possible ifthe above limit values at the switching mechanism are ensured by suitable measures (e. g. siphon). Vacuum Repetition accuracy of the switching points Vibration strength Mechanical life Isolation values Oil and grease-free All pressure switches can operate under vacuum, the device is not damaged by this. < 1 % of the working range (for pressure ranges > 1bar) Up to 4 g no noteworthy deviations. The switching difference is reduced slightly at higher accelerations. Use over 25 g not permissible. With sinusoidal pressure application and room temperature, 10 x 10 6 switching cycles. The expected life depends strongly upon the type of pressure application, therefore this figure can serve only as rough estimate. With pulsating pressure or pressure impacts in hydraulic systems, pressure surge reduction is recommended. Overvoltage category III, contamination class 3, reference surge voltage 4000 V. The conformity to DIN VDE 0110 (01.89) will be confirmed. The parts of all pressure switches in contact with the medium are oil and grease-free. The sensors are hermetically encapsulated, they contain no seals. 12
Pressure Switches and Pressure Monitors Optional function / connection diagrams Plug Teminal Connection diagrams Explanation connection connection Series 200 (IP 54) Series 300 (IP 65) Normal version (plug connection) microswitch, single pole switching over, switching differential not adjustable. Terminal connection housing... 301 (series 300) Adjustmentofswitchingdifference...VorZF203 Maximum limiter ZF 205 See with manual reconnection block. DWR- Interlocking with increasing pressure. series Minimum limiter ZF 206 See with restart outlock. DWR- Interlocking with falling pressure. series Two microswitches, switching in parallel ZF 307 or in succession. Fixed switching interval. Terminal connection case. Please state circuit diagram (see data sheet S 2, page 24 27). Two microswitches, 1 plug ZF 217 switching in succession, adjustable switching interval. Please state circuit diagram (see data sheet S 2, page 24 27). More information about 2-stage pressure switches see data sheet S 2 (page 24 27) Gold-plated contacts ZF 213 Single pole switching over. Cannot be supplied with adjustable switching differential. Switching capacity: max.: 24 V DC, 100 ma min.: 5VDC, 2mA 13
Pressure Switches and Pressure Monitors Optional functions for EExi equipment ZF 5... EEx-i equipment: x Housing (500) with terminal connection (IP 65), blue cable entry and blue terminals. x Partially with resistance combination for line breakage and short circuit monitoring (with isolating switching amplifier Ex 041, see page 48). Important: All pressure switches with the optional functions listed here can be operated only together with a suitable isolating switch amplifier. (See page 48). Type Connection diagram Isolatingswitching amplifier Gold-plated contacts, single-pole switch-over. Switching differential permanent (not adjustable). Switching capacity: max. 24 V DC, 100mA,min.5VDC,2mA. ZF 513 Ex 011 Versions with resistance combination for short circuit and wire breakage monitoring, see DBS series, page 40 42: Normally closed contact with resistance combination for maximum pressure monitoring. Gold-plated contacts. ZF 576 Ex 041 Housing with surface protection. (Chemical version). Normally closed contact with reclosing lock-out and resistance combination for maximum pressure monitoring. ZF 577 Ex 041 Housing with surface protection. (Chemical version). Normally closed contact with resistance combination for minimum pressure monitoring. Gold-plated contacts. ZF 574 Ex 041 Housing with surface protection. (Chemical version). Normally closed contact with reclosing lock-out and resistance combination for minimum pressure monitoring. ZF 575 Ex 041 Housing with surface protection. (Chemical version). 14
Pressure Switches and Pressure Monitors Switch units / optional functions / Adjustment / Documents Description Plug Terminal Connection diagrams connection connection Series 200 Series 300 (IP 54) (IP 65) Plug connector with position indication 12 V 220 V AC/DC ST 218 Protection type IP 65 and switch housing with surface protection (Chemical version) ZF 351 Example: Ordering text: DWR 6 205 Pressure switch DWR 6 205 Code of switching unit or DWR 6 with ZF 205 (e. g. maximum limiter) Code of pressure range Sensor system Plug Terminal connection connection Series 200 Series 300 Adjustment according to customer s instruction: one switching point ZF 1970* ZF 1970* two switching points or defined switching differential ZF 1972* ZF 1972* Adjustmentandsealingaccordingtocustomer sinstruction: one switching point ZF 1971* two switching points or defined switching differential ZF 1973* Document stating adjustment values ZF 1975* Label of units according to customer s instruction ZF 1978 ZF 1978 Special packing for oil and grease-free storage ZF 1979 ZF 1979 Documents: additonal documents, e. g. data sheets, mounting DOKU DOKU instructions, TÜV-, DVGW- or PTB-certificate. Certificates according to EN 10 204 Test report 2.2, type series certificate WZ 2.2 WZ 2.2 AZ 3.1 B Inspection certificate, specific product test AZ 3.1 B AZ 3.1 B Inspection certificate for separating membranes AZ 3.1 B V AZ 3.1 B V * Switching point adjustment: please specify switching point and direction of action (rising or falling presure). 15
Pressure switches Adjustment instructions Adjusting the pressure switches Slight deviations between setting value and switching point are unavoidable due to tolerances and spreads in the characteristics of the sensors and springs, as well as due to friction and the switching kinematics. The pressure switches are adjusted as a rule so that the setpoint adjustment and the actual switching pressure agree best in the middle range. Possible deviations are distributed towards both sides evenly. In the factory adjustment, which is performed on each individual unit, the scale value and the relevant switching point must be brought into agreement. This can be done in two ways: 1. Adjustment at the lower switching point The setpoint x S corresponds to the lower switching point, the upper switching point x O is higher by the switching differential x d. 2. Adjustment at the upper switching point The setpoint x S corresponds to the upper switching point, the lower switching point x U is lower by the switching differential xd. Setting the switching pressures Clockwise: lower switching pressure Counterclockwise: higher switching pressure The type of adjustment which was selected is stated in the technical data of the relevant type series. Before the adjustment, loosen the set screw located above the scale by approx. 2 turns and tighten it again after the setting. The switching pressure is set on the spindle. The set switching pressure can be read off on the scale. Accurate setting of the switching points is possible only with a pressure gauge. Direction of action of the adjustment spindle Changing the switching differential Clockwise: larger differential Counterclockwise: smaller differential (only for switching mechanism with suffix V, ZF 203) By means of set screw inside the spindle. The lower switching point is not changed by the differential adjustment, only the upper switching point is shifted by the differential. The switching differential changes by 1/4 of the total differential range for one turn of the differential screw. The switching differential is the hysteresis, i.e. the pressure difference between switching point and switching back point. For steam pressure switches of the type series DWAMV and DWR-203, the direction of action of the differential screw is reversed. Lead seal of the adjustment spindle (only for plug connection housing 200) The adjustment spindle for setpoint and switching differential can be covered and sealed with the sealing parts available as accessories (type designation: P) consisting of sealing plate and capstan headed screw. The sealing parts can also be attached subsequently. The lacquered adjustment screws are also covered with them. 16
Pressure limiters with switching status lock (restart lockout) In limiter functions it is frequently necessary to retain and lock the shutdown status and to release the lock and switch on the system again only after the causes that led to the safety shutdown have been eliminated. There are two possibilites for this: 1. Mechanical lock inside the pressure switch A bistable microswitch is built into the limiters instead of the microswitch with automatic reset. When the value set on the scale is reached, the microswitch switches over and remains in this position. The lock must be released by pressing the unlocking button (marked by a red dot on the scale side of the switching device). According to version, the lock can be effective with rising or falling value. Unlocking can take place only if the pressure has dropped by a certain amount or in the case of locking it has risen back to the lower switching point. When the pressure limiter is selected, a distinction must be made between maximum pressure and minimum pressure monitoring. EEx-d-versions cannot be delivered with internal locking. 1.1 Maximum pressure limitation Switching over and locking with rising pressure. Additional function ZF 205. Connection to terminal 1 and 3 1.2 Minimum pressure limitation Switching over and locking with falling pressure. Additional function ZF 206. Connection to terminal 2 and 3 2. External electrical interlock in the switchgear cabinet A pressure monitor (microswitch with automatic reset) can also be used as limiter if an electrical interlock is connected in series. In pressure limitation in steam and hot water boilers, the external interlock is permissible only if it is ensured that the pressure monitor is of special construction. 2.1 Maximum pressure limitation with external interlock 2.2 Minimum pressure limitation with external interlock DW = pressure monitor T1 = STOP T2 = START S = signal (as required) K1 = relay with self-hold DW = pressure monitor T1 = STOP T2 = START S = signal (as required) K1 = relay with self-hold safety circuit safety circuit When the interlock circuit shown above is used, the requirements in accordance with DIN 57116/VDE 0116 are fulfilled if the electrical equipment such as contactors or relays of the external interlock circuit correspond to VDE 0660 of VDE 0435 respectively. 17
Type code Explanation of the type designations The type designation of the FEMA pressure switches consist of a letter combination and a subsequent number which identifies the setting range. Additional functions and design alternatives are given an additional code number which is separated from the basic type by a hyphen. Ex version (type of protection against explosion EEx-d) are identified by an Ex in front of the type designation. Basic version with additional function Ex version (exemplified by the DCM series) DCM XXX DCM XXX-YYY Ex-DCM XXX DCM (V) XXX DCM n Identification of the series (e. g. DCM) DCMV n DCM series with adjustable switching differential XXX n Code numbers for the pressure range YYY n Identification for additional functions Ex- n Identification for Ex version Version of the switching housing DCM XXX Basic version with plug connection housing DCM XXX-2... Basic version with plug connection housing DCM XXX-3... Terminal connection housing (300) Ex-DCM XXX EEx-d switching mechanism (700) DCM XXX-5... EEx-i-version Which optional function matches with which pressure switch? Plug connection series 200 Terminal connection series 300 Additional function ZF Additional function ZF 574 575 203 213 217 301 307 513 576 577 EEx-d DCM /VCM x 1 x x 1 x x 1 x x DNM/VNM/DNS/VNS x 1 x x 1 x x 1 x x DWAM x x x x x DDCM x x 2 x x 2 x x DWR x x x x x x x DGM x x x x x x x available 1 with the exception of DCM 4016, DCM 4025, VCM 4156 and DCM 1000 2 with the exception of DDCM 252, 662, 1602, 6002 Ex versions (EEx-d) can only be delivered in the basic version. Additional functions are not possible. 18
Type series DCM Pressure switches and Pressure monitors for overpressure for non aggressive liquid and gaseous media Technical Data Pressure connection External thread G (pressure gauge connection) acc. to DIN 16 288 and internal thread G [ acc. to ISO 228 part 1 Switching device Rugged housing (200) of seawater resistant aluminium die casting GD Al Si 12. Type of protection IP 54, with vertical fitting position. Material of pressure sensor DCM 3... DCM 63 Metal bellows: 1.4571 Sensor housing: 1.4104 DCM025 DCM1 Metal bellows: Cu Sensor housing: Cu + Ms DCM 4016/DCM 4025 Diaphragm: Perbunan Sensor housing: 1.4301 DCM 1000 Diaphragm: Perbunan Sensor housing: Ms Fitting position Vertically upwards and horizontal DCM 4016 and 4025 vertically upwards. Max. ambient temperature at the switch unit 25...+70hC Exception: DCM 4016. DCM 1000: 15... +60 hc EEx-d versions: 15... 60 hc Max. temperature of the medium The maximum temperature of the medium at the pressure sensing element must not exceed the allowable temperature at the switching device. Temperatures up to 85 hc are allowable for short periods (not EEx-d version). Higher temperatures of the medium are possible, provided that the upper limit at the switching device is safeguarded by suitable measures (e. g. water tube trap). Installation Directly in the pressure line (pressure gauge connection) or on a flat surface with2(4mm)screws. Switching pressure Adjustable externally by means of screw-driver. Switching differential Not adjustable in the case of DCM and Ex-DCM. Externally adjustable in the case of DCMV. For values see Summary of types. Methods of sealing As required (may also be carried out after mounting). Adjustment Scale value corresponds to the lower switching point, the upper switching point is higher by the switching differential. Contact agreement Single-pole change-over switch Switching capacity 250 V Ù 250V 24V (ohm) (ind) (ohm) (ohm) Normal 8A 5A 0.3A 8A EEx-d 3A 2A 0.03A 3A Type overview DCM 025 DCM 25 Type Range of Switching diff. Max. Materials* Dimenadjustment (Mean value) allowable sional pressure drawing Switching difference not adjustable DCM 4016 1...16mbar 2mbar 1bar Perbunan DCM 4025 4...25mbar 2mbar 1bar +1.4301 1+11 DCM 1000 10... 100 mbar 12 mbar 10 bar Perb. + Ms DCM 025 0.04...0.25bar 0.03bar 6bar DCM 06 0.1...0.6bar 0.04bar 6bar Cu+Ms 1+14 DCM 1 0.2...1.6bar 0.04bar 6bar DCM 3 0.2...2.5bar 0.1bar 16bar DCM 6 0.5...6bar 0.15bar 16bar DCM 625 0.5...6bar 0.25bar 25bar 1.4104 DCM 10 1...10bar 0.3bar 25bar + DCM 16 3...16bar 0.5bar 25bar 1.4571 DCM 25 4...25bar 1.0bar 60bar 1 + 15 DCM 40 8...40bar 1.3bar 60bar DCM 63 16...63bar 2.0bar 130bar Switching difference adjustable DCMV 025 0.04...0.25bar 0.03...0.4bar 6bar DCMV 06 0.1... 0.6bar 0.04...0.5bar 6bar Cu+Ms 1+14 DCMV 1 0.2...1.6bar 0.07...0.55bar 6bar DCMV 3 0.2...2.5bar 0.15...1.5bar 16bar DCMV 6 0.5...6bar 0.25...2.0bar 16bar DCMV 10 1...10bar 0.5...2.8bar 25bar 1.4104 DCMV 16 3...16bar 0.7...3.5bar 25bar + 1+15 DCMV 25 4...25bar 1.3...6.0bar 60bar 1.4571 DCMV 40 8...40bar 2.0...6.6bar 60bar DCMV 63 16...63bar 3.0...10bar 130bar For smaller pressure ranges see also VCM, DGM, DPS and HCD data sheets. The above pressure switches can also be supplied with optional functions, see ZF data sheet. -version, (housing 700), Ex-degree of protection EEx-d Ex-DCM 4016 1...16mbar 2mbar 1bar Perbunan 3+11 Ex-DCM 4025 4...25mbar 2mbar 1bar Perbunan 3+11 * Cu + Ms = Copper + Brass Stainless steel 1.4104 AISI 430 F 19
Type series VCM Negative Pressure Switch (Vacuum Switch) Technical Data Pressure connection External thread G A (pressure gauge connection) according to DIN 16 288 and internal thread G [ according to ISO 228 part 1. Switching device Rugged housing (200) of seawater resistant aluminium die casting GD Al Si 12. Type of protection IP 54, with vertical fitting position. IP 65, with EEx-d version. Material of pressure sensor VNM 111 and VNM 301: Metal bellows: 1.4571 Sensor housing: 1.4104 VCM 095, 101 and 301: Metal bellows: Cu Zn Sensor housing: CuZn VCM 4156: Diaphragm: Perbunan Sensor housing: 1.4301 Fitting position Vertically upwards and horizontal. VCM 4156 vertically upwards. Max. ambient temperature at the switching device 25...+70hC EEx-d versions: 15... 60 hc Maximum temperature of the medium The maximum temperature of the medium at the pressure sensing element must not exceed the allowable temperature at the switching device. Temperatures up to 85 hc are allowable for short periods (not EEx-d version). Higher temperatures of the medium are possible, provided that the upper limit at the switching device is safeguarded by suitable measures (e. g. water tube trap). Installation Directly in the pressure line (pressure gauge connection) or on a flat surface with2(4mm)screws. Switching pressure Adjustable externally by means of screw-driver. Switching differential Not adjustable on VCM and Ex-VCM. Adjustable on VCMV. For values see Summary of types. Methods of sealing As required (may also be carried out after mounting). Adjustment Scale value corresponds to the lower switching point, the upper switching point is higher by the switching differential. Contact agreement Single-pole change-over switch Switching capacity 250 V Ù 250V 24V (ohm) (ind) (ohm) (ohm) Normal 8A 5A 0.3A 8A EEx-d 3A 2A 0.03A 3A The FEMA Negative Pressure Switches detect the pressure difference relative to the atmospheric pressure. All data on switching pressure ranges and therefore also the graduation on the switch units are to be understood as the difference in pressure between the atmospheric pressure at any one time and the set switching pressure. The zero reference point on the scale of the unit corresponds to the atmospheric pressure at the time. Type overview VCM 301 VNM 111 Type Range of Switching diff. Max. Dimenadjustment (Mean value) allowable sional pressure drawing Switching difference not adjustable VCM 4156 15...+6mbar 2mbar 1bar 1+11 VCM 301 250...+100mbar 25mbar 1.5bar 1+13 VNM 301 250...+100mbar 45mbar 3bar 1+16 VCM 101 1*...+0.1bar 45mbar 3bar 1+14 VCM 095 0.9...+0.5bar 50mbar 3bar 1+14 VNM 111 1*...+0.1bar 50mbar 6bar 1+16 Switching differential adjustable VCMV 301 250...+100mbar 30...200mbar 1.5bar 1+13 VNMV 301 250...+100mbar 70...500mbar 3bar 1+16 VCMV 101 1*...+0.1bar 80...350mbar 3bar 1+14 VCMV 095 0.9...+0.5bar 90...400mbar 3bar 1+14 VNMV 111 1*...+0.1bar 90...650mbar 6bar 1+16 -version (housing 700), Ex-degree of protection EEx-d Ex-VCM 4156 15...+6mbar 2mbar 1bar 3+11 Ex-VCM 301 250...+100mbar 25mbar 1.5bar 3+13 Ex-VNM 301 250...+100mbar 45mbar 3bar 3+16 Ex-VCM 101 1*...+0.1bar 45mbar 3bar 3+14 Ex-VCM 095 0.9...+0.5bar 50mbar 3bar 3+14 Ex-VNM 111 1*...+0.1bar 50mbar 6bar 3+16 * In the case of very high vacuum, close to the negative pressure of 1 bar which is only theoretically possible, the switch can be adjusted only with reservations on account of the special conditions of vacuum technology. The pressure switch itself will however not be damaged at maximum negative pressure. Above pressure switches can also be supplied with the optional functions, see ZF data sheet. For small pressure ranges see HCD data sheet. 20
Type series DNM Pressure switches with sensor system in stainless steel version Technical Data Pressure connection External thread G A (pressure gauge connection) according to DIN 16 288 and internal thread G [ according to ISO 228 part 1. Switching device Rugged housing (200) of seawater resistant aluminium die casting GD Al Si 12. Type of protection IP 54, with vertical fitting position. IP 65, with EEx-d version. Materials of pressure sensor Sensor housing: 1.4104 Pressure bellow: 1.4571 Fitting position Vertically upwards and horizontal. Max. ambient temperature at the switch unit 25...+70hC EEx-d versions: 15... 60 hc Maximum temperature of the medium The maximum temperature of the medium at the pressure sensing element must not exceed the allowable temperature at the switching device. Temperatures up to 85 hc are allowable for short periods (not EEx-d version). Higher temperatures of the medium are possible, provided that the upper limit at the switching device is safeguarded by suitable measures (e. g. water tube trap). Installation Directly in the pressure line (pressure gauge connection) or on a flat surface with2(4mm)screws. Switching pressure Adjustable externally by means of screw-driver. Switching differential Not adjustable on DNM and Ex-DNM. Adjustable on DNMV. For values see Summary of types. Methods of sealing As required (may also be carried out after mounting). Adjustment Scale value corresponds to the lower switching point, the upper switching point is higher by the switching differential. Contact agreement Single-pole change-over switch Switching capacity 250 V Ù 250V 24V (ohm) (ind) (ohm) (ohm) Normal 8A 5A 0.3A 8A EEx-d 3A 2A 0.03A 3A * Stainless steel 1.4104 AISI 430 F High grade stainless steel 1.4571 AISI (316 Ti) DNM 025 DNM 6 All parts of the DNM series of FEMA pressure switches which come into contact with the medium are made of stainless steel. The pressure sensor is welded without added material. The aluminium switch housing has a high resistance to the corrosive effects of the ambient atmosphere. In order to streamline the product portfolio, most DNM types have been replaced by other types of equal quality. Type overview (and replacements) Type Replace- Range of Switching diff. Max. Dimenment adjustment (Mean value) allowable sional pressure drawing Switching difference not adjustable DNM 506 DGM 506 15...60mbar 10mbar 5bar DNM 516 DGM 516 40... 160 mbar 12 mbar 5 bar 1+12 DNM 525 DGM 525 100... 250 mbar 20 mbar 5 bar DNM 025 * 0.04...0.25bar 0.03bar 6bar DNM 06 DWR 06 0.1...0.6bar 0.04bar 6bar 1+16 DNM 1 DWR 1 0.2...1.6bar 0.06bar 6bar DNM 6 DCM 6 0.5...6bar 0.15bar 16bar DNM 625 DCM 625 0.5...6bar 0.25bar 25bar DNM 10 DCM 10 1...10bar 0.3bar 25bar DNM 16 DCM 16 3...16bar 0.5bar 25bar 1+15 DNM 40 DCM 40 8...40bar 1.3bar 60bar DNM 63 DCM 63 16...63bar 2.0bar 130bar Switching difference adjustable DNMV 06 DWR 06 203 0.1...0.6bar 0.08...0.4bar 6bar DNMV 1 DWR 1 203 0.2...1.6bar 0.1...0.6bar 6bar DNMV 6 DCMV 6 0.5...6bar 0.25...2.0bar 16bar DNMV 16 DCMV 16 3...16bar 0.7...3.5bar 25bar DNMV 40 DCMV 40 8...40bar 2.0...6.6bar 60bar DNMV 63 DCMV 63 16...63bar 3.0...10bar 130bar 1+16 1+15 -version (housing 700), Ex-degree of protection EEx-d Ex-DNM 506 Ex-DGM 506 15...60mbar 10mbar 5bar Ex-DNM 516 Ex-DGM 516 40... 160 mbar 12 mbar 5 bar 3 + 12 Ex-DNM 525 Ex-DGM 525 100... 250 mbar 20 mbar 5 bar Ex-DNM 06 Ex-DWR 06 0.1...0.6bar 25mbar 6bar Ex-DNM 1 Ex-DWR 1 0.2...1.6bar 30mbar 6bar 3+16 Ex-DNM 3 Ex-DWR 3 0.2...2.5bar 60mbar 16bar Ex-DNM 6 Ex-DWR 6 0.5...6bar 0.10bar 16bar Ex-DNM 625 Ex-DWR 625 0.5...6bar 0.20bar 25bar Ex-DNM 10 * 1...10bar 0.15bar 16bar 3+15 Ex-DNM 16 Ex-DWR 16 3...16bar 0.2bar 25bar 3+15 Ex-DNM 25 Ex-DWR 25 4...25bar 0.5bar 60bar Ex-DNM 40 Ex-DWR 40 8...40bar 0.7bar 60bar Ex-DNM 63 * 16...63bar 1.0bar 130bar Ex-degree of protection EEx-i: with ZF 513. Example of ordering: DNM... 513 * remains available 21
Type series DNS Pressure switches with high grade steel sensor system optionally housing with surface protection Technical Data Pressure connection External thread G A (pressure gauge connection) according to DIN 16 288 and internal thread G [ according to ISO 228 part 1. Switching device Rugged housing (200) of seawater resistant aluminium die casting GD Al Si 12. Type of protection IP 54, with vertical fitting position. IP 65, with EEx-d-version. Materials of pressure sensor Pressure bellow, and all parts connectedtothemedia:x6crnimoti17122 Material No. 1.4571. Fitting position Vertically upwards and horizontal. Max. ambient temperature at the switching device 25...+70hC EEx-d versions: 15... +60 hc Maximum temperature of the medium The maximum temperature of the medium at the pressure sensing element must not exceed the allowable temperature at the switching device. Temperatures up to 85 hc are allowable for short periods (not EEx-d version). Higher temperatures of the medium are possible, provided that the upper limit at the switching device is safeguarded by suitable measures (e. g. water tube trap). Installation Directly in the pressure line (pressure gauge connection) or on a flat surface with2(4mm)screws. Switching differential See Summary of types. Methods of sealing As required (may also be carried out after mounting). Adjustment Scale value corresponds to the lower switching point, the upper switching point is higher by the switching differential. Contact agreement Single-pole change-over switch Switching capacity 250 V Ù 250V 24V (ohm) (ind) (ohm) (ohm) Normal 8A 5A 0.3A 8A EEx-d 3A 2A 0.03A 3A Surface protection The aluminium die-cast housing made of GD Al Si is chromated and enamelled with resistant plastic. Corrosion tests with 3 % salt solution and 30 temperature changes from +10 to +80 hc showed no changes of the surface at all after 20 days. The pressure switches of series DNS are suitable for monitoring and controlling pressures in devices of the chemical industry and in the process engineering as well as wherever the pressure of aggressive liquids and gases has to be monitored. All component parts of the sensor system are made of high-grade refined steel (1.4571) and are welded by using the latest techniques without additional materials. The pressure sensor is hermetically encapsulated and does not contain any seal material. Type overview DNS 3 201 EX-DNS 3 Type Range of Switching diff. Max. Dimenadjustment (Mean value) allowable sional Pressure drawing Switching difference not adjustable VNS 301 201 250...+100mbar 45mbar 3bar VNS 111 201 1*...+0.1bar 50mbar 6bar DNS 025 201 0.04...0.25bar 30mbar 6bar 1+16 DNS 06 201 0.1...0.6bar 40mbar 6bar DNS 1 201 0.2...1.6bar 60mbar 6bar DNS 3 201 0.2...2.5bar 0.1bar 16bar DNS 6 201 0.5...6bar 0.15bar 16bar DNS 10 201 1...10bar 0.3bar 16bar 1+15 DNS 16 201 3...16bar 0.5bar 25bar Housing with surface protection VNS 301 351 250...+100mbar 45mbar 3bar VNS 111 351 1*...+0.1bar 50mbar 6bar DNS 025 351 0.04...0.25bar 30mbar 6bar 2+16 DNS 06 351 0.1...0.6bar 40mbar 6bar DNS 1 351 0.2...1.6bar 60mbar 6bar DNS 3 351 0.2...2.5bar 0.1bar 16bar DNS 6 351 0.5...6bar 0.15bar 16bar DNS 10 351 1...10bar 0.3bar 16bar 2+15 DNS 16 351 3...16bar 0.5bar 25bar -version (casing 700), Ex-degree of protection EEx-d Ex-VNS 301 250...+100mbar 45mbar 3bar Ex-VNS 111 1*...+0.1bar 50mbar 6bar Ex-DNS 025 0.04...0.25bar 30mbar 6bar 3+16 Ex-DNS 06 0.1...0.6bar 40mbar 6bar Ex-DNS 1 0.2...1.6bar 60mbar 6bar Ex-DNS 3 0.2...2.5bar 0.1bar 16bar Ex-DNS 6 0.5...6bar 0.15bar 16bar Ex-DNS 10 1...10bar 0.3bar 16bar 3+15 Ex-DNS 16 3...16bar 0.5bar 25bar Ex-degree of protection EEx-i with ZF 513 Example for ordering: DNS... -513 * In the case of very high vacuum, close to the negative pressure or 1 bar which is only theoretically possible, the switch can be adjusted only with reservations on account of the special conditions of vacuum technology. The pressure switch itself will however not be damaged at maximum negative pressure. 22
Type series DDC Differential pressure monitors Technical data Pressure connection Internal thread G [ Switching device Rugged housing (200) of seawater resistant aluminium die casting GD Al Si 12. Type of protection IP 54, with vertical fitting position. IP 65, with EEx-d-version. Materials of the pressure sensor DDCM 014 16: pressure bellows: 1.4571 sensor housing: 1.4305 DDCM 252 6002 diaphragm of Perbunan. Sensor housing of aluminium. Fitting position Optional, preferably vertically upwards. Max. ambient temperature at the switching device 25...+70hC EEx-d versions: 15... 60 hc Maximum temperature of the medium The maximum temperature of the medium at the pressure sensing element must not exceed the allowable temperature at the switching device. Temperatures up to 85 hc are allowable for short periods (not EEx-d version). Higher temperatures of the medium are possible, provided that the upper limit at the switching device is safeguarded by suitable measures (e. g. water tube trap). Installation Directly in the pressure line (pressure gauge connection) or on a flat surface with2(4mm)screws. S ( ) = lower pressure P (+) = higher pressure Switching pressure Adjustable externally by means of screwdriver. Switching differential Not adjustable. For values see Summary of types. Adjustment Scale value corresponds to the lower switching point, the upper switching point is the switching differential higher. Methods of sealing As required (may also be carried out after fitting). Scale Types 252 6002 without graduation. Adjustment with a pressure gauge. Switching capacity 250 V Ù 250V 24V (ohm) (ind) (ohm) (ohm) Normal 8A 5A 0.3A 8A EEx-d 3A 2A 0.03A 3A The FEMA differential pressure monitors are suitable for monitoring and controlling differential pressures, flow monitoring and automatic checking of filter plants. A double chamber system with stainless steel bellows resp. perbunan diaphragm accurately detects the difference between the two applied pressures.the differential pressure to be monitored is infinitely adjustable within the ranges mentioned in the summary of types. The settings relate to the lower switching point (in the case of falling differential pressure); the upper switching point (in the case of rising differential pressure) is the value of the switching difference higher. All differential pressure control switches can also be used in the negative pressure area. Every pressure switch has two pressure connections. Type overview Ex-DDCM DDCM 252 Type Range of adjustment Switching diff. Max. Dimen- (differential pressure) (Mean value) allowable sionalpressure drawing DDCM 252 * 4...25mbar 2mbar 0.5bar DDCM 662 * 10...60mbar 15mbar 1.5bar DDCM 1602 * 20... 160 mbar 20 mbar 3 bar DDCM 6002 * 100... 600 mbar 35 mbar 3 bar 1+17 DDCM 014 0.1...0.4bar 0.15bar 15bar DDCM 1 0.2...1.6bar 0.13bar 15bar DDCM 4 * 1...4bar 0.20bar 25bar DDCM 6 0.5...6bar 0.2bar 15bar 1+18 DDCM 16 3...16bar 0.6bar 25bar * Without graduation (only ± scale) For optional functions see ZF data sheet. For smaller pressure ranges see HCD and DPS data sheet. -versions available (Ex degree of protection EEx-d). Type: Ex-DDCM... Accessories: Valve combination for differential pressure switch x Screw union with screw in nipple G [ /8 mm MAU 8/MS and MAU 8/Nst x Valve combination VKD 3 and VKD 5 3-fold and 5-fold valve block for installation in the differential pressure line. Suitable for the differential pressure switch series DDCM 014 to DDCM 16 Materials: Housing 1.4404, inner parts 1.4571 Gaskets: PTFE Process connections: 1/2 14 NPT Scope of supply: Complete with screw unions and formed pipe pieces For further information see page 51. 23
Type series S2 Pressure Switches with 2 microswitches FEMA Series DCM pressure switches (with the exception of DCM 1000, DCM 4016 and DCM 4025), VCM (with the exception of VCM 4156), VNM, DNS, VNS and DDCM (with the exception of DDCM 252, 662, 1602 and 6002) differential pressure monitors can be fitted with 2 microswitches. This is not possible with any other series or on explosion-proof versions. Technical Data Basic complement Switching interval Switching differential Options The technical data of the two-stage pressure switches are contained in the data sheets applicable to the basic types in question. This also applies to all application limits, such as temperature, max. pressure, installation position, degree of protection, electrical data, etc. The principal dimensions are also the same as for the single-stage pressure switches with comparable pressure ranges and configurations. The basic complement of every two-stage pressure switch includes a switching device with 2 microswitches, single-pole switchover in each case. Switch I is used to monitor the lower pressure and Switch II the higher. The setting ranges stated in the data sheets for the basic types are exactly the same for two-stage pressure switches. It should be noted that the switching differentials of the individual microswitches cannot be exactly identical on account of component tolerances. The switching interval of the two microswitches is the interval (in bar or mbar) between the switching points of the two microswitches. Example: As pressure increases, a two-stage pressure switch switches on a warning light at 2.8 bar; if pressure continues to increase, the system is shut off at 3.2 bar. The switching interval is 3.2 2.8 = 0.4 bar. The following applies to all versions: The switching interval remains constant over the entire setting range of the pressure switch. When switching pressure settings are altered with the setting spindle S, the switching interval does not change; the switching points are displaced parallel to one another. The switching differential, i. e. the hysteresis of the individual microswitches, corresponds to the values for the basic types as stated in the Type Overview. In the case of two-stage pressure switches, the switching differential of the individual microswitches is not adjustable. Two-stage pressure switches are available in 3 different versions, each of which is identified by a ZF No. The various versions differ in their connection diagrams and in their electrical connection (terminal or plug connection). Additional Switching interval Electrical connection Connection diagram Ordering data required function between the two micro-switches ZF 307 Works setting to Terminal connection all 2 x single-pole switchover 1. Basic type with ZF 307 customer specification connections of the two 2. Switching points I and II, microswitches are each with direction of action accessible (6 terminals) (rising of falling pressure) Example: DCM 16 307 Switching point I : 10 bar falling Switching point II: 12 bar falling or only switching interval. ZF 217 Adjustable with Plug connection Connection diagram only 1. Basic type with ZF 217 setting wheels I and II according to DIN 43 650 to be regarded as an 2. Circuit diagram. as per Switching (3-pole + PE conductor). example. Selection as per Example: DCM 16 217/ B 4 Intervals table Functional internal wiring Switching Functions As all values are adjustable as per Switching table within the specified limits, Functions table no further data are required. 24
Type series S2 Pressure Switches with 2 microswitches ZF 217 and switching interval Switching intervals of two-stage pressure switches (ZF 217, ZF 307) Type Series S2 ZF 217 ZF 307 higher pressure lower pressure min. switching interval max. switching interval (average values) Type Works preset Circuit dgr. Circuit dgr. Circuit dgr. A1/A3/B2/B4 A2/A4/C2/C4 B1/B3/D1/D3 C1/C3/D2/D4 +ZF307 DCM 06 25 mbar 165 mbar 190 mbar 140 mbar DCM 025 20 mbar 140 mbar 160 mbar 120 mbar DCM 1 40 mbar 240 mbar 280 mbar 200 mbar DCM 3 0.1 bar 0.65 bar 0.75 bar 0.55 bar DCM 6 0.15 bar 0.95 bar 1.2 bar 0.8 bar DCM 10 0.25 bar 1.6 bar 1.85 bar 1.35 bar DCM 16 0.3 bar 2.0 bar 2.3 bar 1.7 bar DCM 25 0.6 bar 4.0 bar 4.6 bar 3.4 bar DCM 40 0.9 bar 6.0 bar 6.9 bar 5.1 bar DCM 63 1.3 bar 8.5 bar 9.8 bar 7.2 bar DDCM 1 0.09 bar 0.55 bar 0.64 bar 0.46 bar DDCM 6 0.14 bar 0.94 bar 1.08 bar 0.8 bar DNM 06 40 mbar 240 mbar 270 mbar 200 mbar DNM 025 35 mbar 215 mbar 240 mbar 180 mbar DNM 1 50 mbar 300 mbar 350 mbar 250 mbar DNM 506 10 mbar 65 mbar 75 mbar 60 mbar DNM 516 11 mbar 70 mbar 80 mbar 65 mbar DNM 525 12 mbar 70 mbar 80 mbar 65 mbar VCM 095 40 mbar 300 mbar 340 mbar 260 mbar VCM 101 40 mbar 260 mbar 300 mbar 220 mbar VCM 301 20 mbar 100 mbar 120 mbar 80 mbar VNM 111 50 mbar 310 mbar 360 mbar 260 mbar Additional function ZF 217 Switching devices with adjustable switching interval The switching interval is steplessly adjustable with 2 externally accessible setting wheels I and II. The maximum possible switching intervals are stated in the Switching Intervals table. Setting wheel I CWreduce switching point at microswitch I Setting wheel II CCWraise switching point at microswitch II Setting wheels I and II have an internal stop to ensure that the microswitches cannot be adjusted past their effective range. Recommended settings for switching devices with ZF 217 Addition of the adjustment with setting wheels I and II provides the switching interval between the two microswitches. Changes made at the setpoint spindle do not affect the switching interval; the switching interval remains constant over the entire adjustment range of the spindle, the two switching points being displaced up or down in parallel. 1. Move setting wheels I and II to normal position. Turn setting wheel I fully CCW. Turn setting wheel II fully CW. 2. Set setpoint spindle S to a value on the scale which is central between the required top and required bottom switching point. 3. With pressure applied, set bottom switching point with setting wheel I (take into account direction of action pressure rising or falling). 4. With setting wheel II, proceed as under 3. above to set top switching point. 5. If the required top and bottom switching point cannot be obtained, adjust setpoint spindle S in the necessary direction and repeat setting as per 3. and 4. above. 25
Type series S2 Two-stage Pressure Switches Switching functions ZF 217 Internal functioning of the microswitches I and II. Selection table of circuit diagrams. The switching position illustrates pressure free status. The switching function of microswitch I (A D) is shown in the horizontal axis, that of microswitch II (1 4) is the vertical axis. The circuit diagram which meets both criteria can be found at the intersection of the two points (e. g. A 2). Microswitch I (lower switching point) To close, when falling To close, when rising To open, when falling To open, when rising Microswitch II (upper switching point) To open, when rising To open, when falling To close, when rising To close, when falling Ordering specification: When ordering setting or adjustment at the factory with the exception of basic models (e. g. DCM 10) please state the circuit diagram, (e. g. A 2) the switching points and the direction of operation. Example: DCM 10 217/ A 2, switch I: 6.5 bar falling, switch II: 7.5 bar rising. 26
Type series S2 Applications for two-stage pressure switches Example 1: Pressure dependent control of automatic pressure expansion controls and pressure maintenance stations Compressor Pressure monitors with two integral microswitches, which can be caused to switch over consecutively with rising of falling pressure, can considerably simplify monitoring and control of pressures. For example, minimum and maximum pressure monitoring and carried out with asinglepressure switch, thus eliminating the need for a second pressure switch with the installation cost involved. Step switching, for example pressure dependent control of a two-stage pump, is also possible with a pressure switch of this special series. Problem definition Pressure maintenance vessels and automatic pressure expansion controls generally incorporate a gas cushing, whose pressure must be kept constant within a certain range. When pressure is too low, a compressor is switched on; when pressure is excessive, a solenoid valve must be opened for blowing off. In between, there is a neutral zone in which the compressor and solenoid valve are at rest. Solution Suitable for this purpose are all pressure switches of Types DCM, DNM and DNS, each with additional function ZF 217 and circuit diagram A 2. All pressure ranges listed in the technical literature are possible. Specimen order: DCM 6 217/ A 2 Switchting function / Connection diagram Switch I: With falling pressure, contact 1 2 closes (Compressor ON) With rising pressure, contact 1 2 opens (Compressor OFF) Switch II: With rising pressure, contact 2 3 closes (Valve OPEN) With falling pressure, contact 2 3 opens (Valve SHUT) In between, there is a neutral zone in which neither the compressor is switched ON, nor the valve solenoid energized (REST position). Example 2: Maximum and minimum pressure monitoring in a nitrogen line Problem definition In a industrial process plant, the pressure in a nitrogen line is to be monitored. A green pilot light should indicate whether the pressure in the line is between 2.2 and 2.6 bar. If 2.2 bar is undershot or 2.6 bar overshot, the pilot light should extinguish or the plant should be shut down. Solution The first contact of a DCM 3 307 pressure switch with 2 microswitches opens at 2.2 bar as pressure falls; the second microswitch opens at 2.6 bar as pressure rises. If a pressure of > 2.2 bar and < 2.6 bar prevails, the circuit is made via the two microswitches and the pilot light illuminates. Example 3: Filter monitoring with a 2-stage differential pressure manometric switch Problem definition Increasing contamination of a filter system is to be monitored by means of a differential pressure switch. Progressive contamination produces a higher differential pressure between input and output of the filter system. A green pilot light is to indicate normal operating state. When contamination reaches a certain level (differential pressure > 0.9 bar) the attention of the operating personnel is drawn to the necessity for changing the filter elements by a yellow pilot light. If this in not done and the differential pressure rises as a result of continuing contamination (e. g. to > 1.2 bar), the system is to be shut down. Solution A DDCM 6 307 differential pressure switch switches over as differential pressure rises (at 0.9 bar), the green pilot light extinguishes. At the same time, the yellow light comes on (Filter Clean request). If the differential pressure continues to rise (to > 1.2 bar), the circuit is broken via contacts 4 6 of the second microswitch, the relay drops out and the system is shut off. green yellow 27
INFO TÜV DVGW Pressure limiters of special construction Safety considerations and definitions Pressure monitoring and pressure limiting in Steam boilers Hot water heating systems District heating systems Gas installation Firing systems Liquefied gas systems etc. is of great safety engineering importance. Component tested The pressure monitoring devices necessary for this must work reliably and be tested according to the relevant directives in each case.the reliability of pressure monitors and pressure limiters must be certified by a component test which is performed by the testing agencies responsible in each case (e. g. TÜV and DVGW). The following part contains the FEMA production range for pressure monitoring relevant to saftey engineering in thermal and process engineering systems. Of special construction The expression of special construction originates from the VdTÜV pressure Memorandum DRUCK 100/1, issue 04.83 in which the requirements on pressure monitors and pressure limiters for steam boilers and hot water systems are determined. Used originally only for pressure monitoring in the steam and hot water area, the feature of special construction was taken over more and more as quality and safety argument for other applications as well. The following part describes the requirements on pressure limiters of special construction. Recommendations for the correct selection of pressure limiters are given by reference to safety analyses. A few definitions are necessary in advance. In advance some definitons are necessary The VdTÜV Memorandum DRUCK 100/1 distinguishes between the following terms: Pressure monitors (DW) Pressure monitors are devices which switch off the heating system on exceeding and/or not reaching a permanently set pressure limit and free the heating system again only after a change in pressure. Pressure limiters (DB) Pressure limiters are devices which switch off the heating system on exceeding and/or not reaching a permanently set pressure limit and lock this against automatic switching on. Pressure limiters of special construction (SDB) Pressure limiters of special construction fulfil the same tasks as pressure limiters.they must in addition fulfil the requirements regarding the extended safety according to Pressure 100/1, Section 3.3. 28
Pressure limiters of special construction Safe conditions Firstly it is necessary to define the safe condition : According to DIN VDE 0660, Part 209, the safe condition of the system is reached if a cut-off command is present at the output contact which means that in the safe condition, the microswitch in the pressure limiter is actuated (opened) and the control circuit is interrupted. Series connected switching devices must react in the same way. The operating mode of the safety pressure limitation thus corresponds to the closed circuit principle. Additional requirements on pressure limiters of special construction Definition of Section 3.3 of the VdTÜV Memorandum: Pressure limiters of special construction must lead on breakage in the mechanical part of the measuring element to cut-off and interlock of the heating. This requirement is also fulfilled if the mechanical part of the measuring element is calculated for fluctuating loading or has withstood a test with 2 million operating cycles and the pressure loaded parts of the measuring element consist of corrosion-resistant materials. Abbreviated excerpt from VdTÜV Memorandum DRUCK 100/1 Accordingly there are 2 possibilities of fulfilling the requirements according to of special construction : a: By a pressure sensor which is designed so that a breakage in the mechanical part of the measuring element leads to cut-off to the safe side. b: By proof of an endurance test with 2 million operating cycles during the component test. 7 6 Fig. 1: Self-monitoring maximum pressure limiter with safety diaphragm DWAM...,DWAMV...,SDBAM... 8 3 2 1 5 a) Self-monitoring pressure sensor for maximum pressure monitoring Fig. 1 shows the cross-sectional diagram of a pressure sensor which fulfils the requirements on special construction. The measuring chamber is bordered by the housing (1), bottom (2) and measuring bellows (3). All parts consist of non-rusting steel and are welded together with one another without additional materials. On rising pressure the measuring bellows (3) moves upwards, supported by the back pressure spring (5). The setpoint spring installed in the switching mechanism acts as counterforce. A transfer bolt which transfers the pressure-dependent movements of the measuring bellows (3) to the switching mechanism located above is placed on the inside of the bottom. A plastic diaphragm (7), which is not in contact with the medium and in normal operation follows the movements of the measuring bellows but itself has no influence on the position of the bellows, is clamped in the upper part of the transfer bolt. On breakage of the measuring bellows (3), the medium can escape into the interior of the bellows.the medium pressure is now on the lower side of the diaphragm (PL). An additional force is generated because of the clearly larger effective area of the diaphragm compared with the bellows and this pushes the transfer bolt (6) upwards. This leads to cut-off to the safe side. The cut-off condition thus achieved is normally interlocked electrically or mechanically, so that the system also remains cut off when the pressure drops again. The plastic diaphragm (7) is not a pressure-bearing part, it has no function in normal operation and is effective only if a leakage occurs to the measuring bellows. Safety diaphragms of the described design are permissible up to 32 bar, this should be sufficient for most applications. Fig. 2: Pressure limiter without safety diaphragm (not self-monitoring) DWR... b) Pressure sensors with proof of 2 million operating cycles (DWR-series) In this design it is assumed that the pressure sensors which have withstood dynamic loading of 2 million operating cycles during component testing can be considered as reliable elements. They do not have an additional safety device in the sensor. Although the units are produced and tested with very great care, maximum pressure limiters without additional safety device can lead to dangerous conditions if errors which cannot be detected in the tests occur due to secondary effects. The causes for this can be: Hole corrosion due to deposited metal particles on the (usually very thin walled) bellows of the pressure sensor, material defects in the pressure bellows or broken open weld. Despite careful production and testing: A residual risk remains in maximum pressure monitoring. In the final analysis the user and operator of the systems must decide himself with which degree of safety he will monitor his pressure vessels. Pressure sensors without safety diaphragm are self monitoring when used in minimum pressure monitoring applications. 29
Pressure limiters of special construction Safety engineering considerations The direction of action must be observed The preceding description and the safety analytical consideration relate to monitoring the maximum pressure. The safe side here means: Cut off the energy supply (e.g. burner off) to avoid a further pressure rise. A completely different consideration is necessary for monitoring the minimum pressure.the safe side here means: Avoiding the pressure dropping further (example: hot water systems with external pressure retention or monitoring the water level in heating systems).the safety engineering consideration clearly gives preference here to the pressure limiter without safety diaphragm. In the case of leakage in the sensor, lower pressure is signalled and it switches over to the safe side. A pressure sensor without safety diaphragm is therefore of special construction within the meaning of the Memorandum DRUCK 100/1, if it is used as minimum pressure limiter. In reverse one must draw from this consideration the conclusion that pressure sensors with safety diaphragm, which offer considerable advantages in maximum pressure monitoring, may never be used for minimum pressure monitoring. Incorrect use can create a dangerous condition. It is therefore mandatory for the user and planner to observe the direction of action in the selection of the pressure limiters. It can be stated in summary: Pressure limiters of special construction with safety diaphragms offer the highest degree of safety in maximum pressure monitoring. Such devices may be used under no circumstances for minimum pressure monitoring. Pressure limiters of special construction with proof of 2 million operating cycles are selfmonitoring in minimum pressure monitoring, a residual risk remains in maximum pressure monitoring. Safety analysis in maximum pressure monitoring Devices with safety diaphragm (DWAM, DWAMV, SDBAM) If one considers the switch positions in the conceivable operating conditions, then the difference between the pressure sensors in of special construction becomes clear. The left column shows in each case normal operation in which the switch connects the terminals 3 and 1. The cut-off condition at too high pressure is shown in column 2, the control circuit is interrupted through the terminals 3 and 1. The difference produces the safety engineering consideration in column 3 in which the switch position is shown in the case of a leakage in the pressure sensor. The control circuit is interrupted in the case of a sensor in safety technique, whereas with a sensor without safety diaphragm the control circuit remains closed and thus a dangerous condition can arise. In pressure limiters of special construction, which are equipped with safety sensors, the following switch positions result in the different operating conditions: Normal- Limit Leckage in the operation not reached pressure sensor Control Control Control circuit circuit circuit closed interrupted interrupted Devices without safety diaphragm The special construction must also be proven by an endurance test with 2 million operating cycles. In the case of breakage/leakage (e.g. material defect, defect in the welds, hole corrosion), the system does not cut off to the safe side (no selfmonitoring). In the different operating conditions the following switch positions result in maximum pressure monitoring: In the case of leakage in the pressure sensor, the pressure monitors/limiters according to b) are not safe. A dangerous condition can arise. Normal- Limit Leckage in the operation not reached pressure sensor Control Control Control circuit circuit circuit closed interrupted closed!!! Dangerous condition! 30
Safety engineering analysis in maximum pressure monitoring Minimum pressure All minimum pressure monitors and minimum pressure limiters are self-monitoring within the meaning of Druck 100/1. Pressure limiters must interlock the cut-off state The Memorandum DRUCK 100/1 specifies that pressure limiters must cut off and interlock against switching on automatically. For this purpose, pressure limiters are offered with integrated mechanical interlock (reclosing lockout). The direction of action is also important in the selection of the interlock. According to direction of action it must be determined whether the interlock should take place on rising (maximum pressure monitoring) or falling (minimum pressure monitoring) pressure. External interlock is also possible A pressure monitor can become a pressure limiter if an electrical interlock is connected in series. The figures on page 13 show proposals for interlock circuits for maximum pressure and for minimum pressure monitoring. Naturally the direction of action must be observed when determining the circuit. So that the combination of pressure monitor with external interlock can be considered as limiter of special construction, the pressure monitor itself must fulfil the requirements on of special construction. Of special construction not only in steam and hot water systems? According to the current standards situation, pressure limiters of special construction are mandatory only for steam boilers according to TRD 604 and for heating systems according to DIN 4751 Part 2. They are considered to be failproof elements within the meaning of TRD 604 and can therefore be used in installations in 24-hour operation and in 72-hour operation (the TRD 604 contains further details on this). It would be appropriate to transfer the positive experience from pressure monitoring of steam boilers to other applications. Within the meaning of more safety it is desirable also to transfer the requirements on pressure limiters of special construction to other standards in the case of safety-relevant monitoring tasks. This applies especially for applications in the gas area, DIN 3398 Part 1 and 3 is responsible for this and for liquid fuels (DIN 3398 Part 4). Even more safety due to line breakage and short circuit monitoring The safety in maximum pressure monitoring can be increased further by additional measures. The microswitches, normally equipped with step action spring contact, can be equipped with positive opening contact (protection against contact sticking). The supply line to the pressure limiter is monitored for short circuit and interruption by an external isolating switching amplifier. In the case of faults in the supply line, the system cuts off to the safe side. EEx-d and EEx-i versions, combined with sensors of special construction open up the wide field of Ex applications in process engineering systems and in gas engineering. The DBS series is equipped with these additional safety features. It is apparent that safety can be improved significantly by skilful use of technical measures and a number of causes for the occurrence of dangerous conditions can be eliminated. But it is also apparent that a residual risk remains. Careful planning and conscientious maintenance and testing of existing systems are an absolute prerequisite for reliable pressure monitoring on pipelines and pressure vessels. 31
INFO Standards Directives Component tests VdTÜV Pressure 100/1 DVGW DIN 3398 P.1 and 3 TÜV DIN 3398 P.4 TÜV, Pressure 100/1 (DIN 3398 P.3 and P.4) EEx de IIC T6 (pressure proof encapsulated) EEx-ia (intrinsically safe) Steam and hot water Pressure monitors and pressure limiters for steam and hot water in systems to DIN 4751 T2 and TDR 604. Series DA and DWR. Fuel gases Pressure monitors and limiters for fuel gases in accordance with DVGW Worksheet G 260. Series DGM and DWR. Gas appliance directive 90 / 396 EEC for DGM series. Liquid fuels Pressure monitors and pressure limiters for liquid fuels (heating oil). Series DWR. Pressure limiters in safety function for safety-relevant pressure monitoring in liquid gas systems, chemical and processing engineering systems. -versions For Ex areas Zone 1 and 2, all pressure switches can be delivered in pressure-proof encapsulated design (Ex degree of protection EEx de IIC T 6). PTB approval: Ex-90.C.1059 For instrinsically safe control circuits (Ex degree of protection EEx-ia), the pressure switches can be delivered with gold plated contacts, proximity switches as well as with the blue terminals and cable entries customary in the EExi area. An isolating switching amplifier, which transfers the control commands of pressure switch from an instrinsically safety control circuit (EEx, EEx-ia) into a not intrinsically safe active circuit, is required in addition to the pressure switch. Medium Steam Hot water Burnable gases DVGW-worksheet G260/1 Liquid fuels (fuel oil) Pressure vessels (e. g. for liquefied gas) Plant directives DIN 4751 Part 2 TRD 604 Directives for component testing VdTÜV Pressure 100/1 Issue 4.83 DIN 3398 Part 3 Issue 11.82 DIN 3398 Part 4 Issue 10.86 TÜV Pressure 100/1 DIN 3398 T.4 Type series DA DWR... DWR... DGM... DWR... FD... DWAM... 32
INFO Selection of pressure monitors / pressure limiters according to function and area of application Pressure monitor Function Application Pressure monitoring Pressure control (e. g. burner or pump control) Steam and hot water Systems according to TRD 604 and DIN 4751 P. 2 Burnable gases according to DVGW worksheet G 260 Fuel oil and other liquid fuels Other media (compatibility with the materials used must be tested) DWAM xxx DGM xxx DWAM xxx DWAMV xxx DWAMV xxx DWR xxx DWR xxx DWR xxx DWR xxx DWR xxx-203 DWR xxx-203 DWR xxx-203 DWR xxx-203 Maximum pressure limitation with internal SDBAM xxx DGM xxx-205 SDBAM xxx interlock DWR xxx-205 DWR xxx-205 DWR xxx-205 DWR xxx-205 with external DWAM xxx DGM xxx DWAM xxx interlock DWR xxx DWR xxx DWR xxx DWR xxx Minimum pressure limitation with internal DGM xxx-206 interlock DWR xxx-206 DWR xxx-206 DWR xxx-206 DWR xxx-206 with external DGM xxx interlock DWR xxx DWR xxx DWR xxx DWR xxx xxx Here the code number for the pressure range must be inserted in each case (see datasheets). Switching devices with the end No. 2... means plug connection according to DIN 43 650 (example DWR xxx-205). Unlocking Pressure limiter with internal interlock INFO Equipment of a boiler with pressure monitor and pressure limiter (proposal) Pressure monitor for burner control DWAM... or DWR... (without adjustable switching differential) or (better, because switching differential adjustable) DWAM...orDWR... 203 Pressure monitor DWAM... ordwr... Pressure limiter SDBAM... ordwr... 205 Pressure limiter for safety monitoring: SDBAM... or DWR... 205 (with internal interlock, unlocking button on the pressure limiter) or DWAM...orDWR...(with external interlock in the control cabinet) Connection proposal for the external interlock seepage14. 33
INFO Selection of the pressure monitors / pressure limiters for steam and hot water systems according to TRD 604, DIN 4751, P. 2 Selection diagrams Minimum pressure monitors (DRW series) can also be used as protection against running dry for installations up to 350 kw. INFO Replacement of previous types by the DWR series * The pressure monitoring devices of the newer DWR... series are of the same construction as the previous type series. Only the adjustment range of the DWR type series is slightly different in the minimum pressure switches of the types DWUM / DBUM 8 and 16. ThetypeseriesDWUM...andDBUM...arestill available up to expiry of the registration numbers (beginning of 1999). New series Previous series DWR DGM DNA DWUM DBUM DWR 06 DWUM 06 DWR 1 DWUM 1 DWR 3 DNA 3 DWR 6 DGM 6 DNA 6 DWUM 8* DWR 625 DGM 6 DNA 6 DWUM 625 DWR 16 DNA 10 DWR 16 DGM 16 DNA 16 DWUM 18* DWR 25 DGM 25 DNA 25 DWR 06-206 DBUM 06 DWR 1 206 DBUM 1 DWR 6-206 DBUM 8* DWR 625-206 DBUM 625 DWR 16-206 DBUM 18* 34
Technical Data Type series DA Pressure connection External thread G A (pressure gauge connection) to DIN 16 288 and internal thread G [ to ISO 228 Part 1. Switching device Rugged housing (200) of aluminium die casting GD Al Si 12 (Good resistance to seawater). Materials Pressure bellows: Material No. 1.4571 Sensor housing: Material No. 1.4104 Switching housing: GD-Al Si 12 according to DIN 1725 Fitting position vertically upwards and horizontal. Ex-versions: only vertically. Ambient temperature at the switching device 20 to 70 hc. Maximum temperature of the medium: 20 to 70 hc. The maximum temperature of the medium at the pressure sensing element must not exceed the allowable temperature at the switching device. Temperatures up to 85 hc are allowable for short periods. Higher temperatures of the medium are possible, provided that the upper limit at the switching device is safeguarded by suitable measures (e. g. water tube trap). Fitting Direct on pressure line (pressure gauge connection), or on a wall with 2 off 4mmscrews. Adjustment In the case of max. pressure switches: The pressure monitors and the safety pressure limiting devices are adjusted so that with increasing pressure the change-over takes place at the set switching pressure. Switching back when pressure falls occurs at a pressure which is lower by the amount of the switching differential or, in the case of pressure limiting devices and safety limiting devices, by the falls in pressure specified in the table. The scale value corresponds to the upper switching point. Switching differential See Table of types. Contact agreement Single-pole change over switch. Switching capacity 250 V Ù 250V 24V (ohm) (ind) (ohm) (ohm) Normal 8A 5A 0.3A 8A Sealing Generally available for safety pressure limiting devices SDBAM. For pressure monitor switches upon request. Bursting pressure For all types 100 bar. Verified by TÜV test. Maximum pressure monitors and limiters with selfmonitoring sensor Component tested for Steam Systems according to TRD 604 Hot water Systems according to DIN 4751, P. 2 Testing basis VdTÜV-Memorandum Druck 100/1 TÜV-Registration No. TÜV DW 99 132 for series DWAM... TÜV DW 99 133 for series DWAMV... TÜV SDB 99 134 for series SDBAM... Function Pressure monitor / Pressure limiter Direction of action Sensor Type overview Maximum pressure monitoring (F) For max. pressure monitoring TÜV TESTED Of special construction due to selfmonitoring Type Range of Switching Maximum* Dimens. adjustm. differential operating drawing (Mean value) pressure (bar) (bar) (bar) Pressure monitors without differential adjustment for max. pressure monitoring DWAM 06 0.1...0.6 0.04 5 DWAM 1 0.2...1.6 0.05 5 1+16 DWAM 6 1.2...6 0.2 10 DWAM 16 3...16 0.4 20 1+15 DWAM 32 6...32 1.2 45 Pressure monitors with differential adjustment for max. pressure monitoring DWAMV 1 0.2...1.6 0.12...0.6 5 1+16 DWAMV 6 1.2...6 0.4...1.5 10 DWAMV 16 3...16 0.8...2.5 20 1+15 DWAMV 32 6...32 2.5...6.0 45 Pressure limiters with internal interlock for maximum pressure monitoring Pressure change for interlocking SDBAM 1 0.2...1.6 0.12 5 SDBAM 2.5 0.4...2.5 0.15 5 SDBAM 6 1.2...6 0.4 10 SDBAM 625 1.2...6 0.6 20 SDBAM 16 3...16 0.8 20 SDBAM 32 6...32 3.0 45 1+16 1+15 * The maximal permissible operating pressure is defined as the upper limit at which the operation, the switching reliability and the water tightness of the pressure switch are in no way impaired. The pressure monitors DWAM... can also be used for maximum pressure limitation, by using an external interlock (page 17). Minimum Pressure monitoring (G) The types DWUM... and DBUM... are substituted by DWR-series (page 36 and 37). Seealsopage34. 35
Type series DWR Pressure monitors, component tested for steam, hot water, burnable gases and liquid fuels and -versions Technical data Pressure connection External thread G A (pressure gauge connection) according to DIN 16 288 and internal thread G [ according to ISO 228 Part 1 (for gas applications internal thread permissible only up to 4bar). Switching device Stable housing (200) made of sea water resistant aluminium die casting. Materials Pressure bellows: Material No. 1.4571 Sensor housing: Material No. 1.4104 Switch housing: GD Al Si 12 (DIN 1725) Installation position Vertical and horizontal. In Ex version only vertical. Ambient temperature at the switching device 25 to 70 hc, for EEx-d version 15 to +60 hc. Medium temperature 25 to 70 hc. The maximum medium temperature at the pressure sensor may at the most be equal to the permissible ambient temperature at the switching device. Briefly acting temperatures up to 85 hc are permissible (not EEx-d version). Higher medium temperatures are possible if the above limits at the switching device are ensured by suitable measures(e.g.waterpockettube). Installation Directly on the pressure line (pressure gauge connection) or on a level surface with2screws4mmdia. Switching pressure Adjustable from the outside by means of screwdriver. The scale value corresponds to the lower switching point (for falling pressure), the upper switching point (for rising pressure) is higher by the switching difference. Exception: DWR... 203. Bursting pressure For all types 100 bar, verified by TÜV test. Switching difference For values see type overview. Contacts Single-pole changeover switch. Switching capacity 250 V Ù 250V 24V (ohm) (ind) (ohm) (ohm) Normal 8A 5A 0.3A 8A EEx-d 3A 2A 0.03A 3A Degree of protection IP 54 according to DIN 40 050 IP 65 (alternative version) Ex ignition degree of protection EEx de IIC T6 PTB approval Ex 90.C.1059 EEx-i with ZF 513 Degree of protection of EEx-d version IP 65, installation position only vertical. Possibility of lead sealing On request (can also be fitted subsequently). Component tested for Steam Systems according to TRD 604 Hot water Systems according to DIN 4751, P. 2 Burnable gases DVGW work sheet G 260 Liquid fuels e. g. fuel oils Testing basis Registration No. Pressure 100/1*, Issue 4.83 TÜV.DWFS (SDBFS) 00 281 DIN 3398, P. 3, Issue 11.82 NG-4346 AQ 1411 DIN 3398, P. 4, Issue 10.86 3 C02 895 Function Direction of action Sensor Type overview Pressure monitor or Pressure limiter (with external interlock) For max. pressure and min. pressure monitoring Of special construction by test with 2 million switching cycles. (DWFS, SDBFS) Type Setting Switching Maximum Dimensional range difference operating drawing (Mean values) pressure (bar) (bar) 1* 2* Switching difference not adjustable DWR 06 0.1...0.6bar 0.04 DWR 1 0.2...1.6bar 0.06 DWR 3 0.2...2.5bar 0.1 DWR 6 0.5...6bar 0.2 DWR 625 0.5...6bar 0.25 DWR 16 3...16bar 0.5 DWR 25 4...25bar 1.0 DWR 40 8...40bar 1.3 EEx-ia version with ZF 513 (page 14) Switching difference adjustable DWR 06 203 0.1...0.6bar 0.08...0.5 DWR 1 203 0.2...1.6bar 0.15 0.6 DWR 3 203 0.2...2.5bar 0.17...1.2 DWR 6 203 0.5...6bar 0.2...1.4 DWR 625 203 0.5...6bar 0.4...2.5 DWR 16 203 3...16bar 0.75 3.15 DWR 25 203 4...25bar 1.3...6.0 DWR 40 203 8...40bar 2.3...6.6 TÜV DVGW 6 6 1 + 16 10 16 1 + 15 20 25 1 + 15 50 63 1 + 15 6 6 1 + 16 10 16 1 + 15 20 25 1 + 15 50 63 1 + 15 -versions (EEx de IIC T6) e. g. for burnable gases (housing 700) Ex-DWR 06 0.1...0.6bar 0.04 Ex-DWR 1 0.2...1.6bar 0.06 6 6 3 + 16 Ex-DWR 3 0.2...2.5bar 0.1 Ex-DWR 6 0.5...6bar 0.2 10 16 3 + 15 Ex-DWR 625 0.5...6bar 0.25 Ex-DWR 16 3...16bar 0.5 20 25 3 + 15 Ex-DWR 25 4...25bar 1.0 Ex-DWR 40 8...40bar 1.3 50 63 3 + 15 * Maximum operating pressure Column 1: For devices according to DIN 3398, Part 3 (gas pressure monitors) Column 2: For devices according to pressure 100/1 and DIN 3398, Part 4 (for steam, hot water and liquid fuels) 36
Type series DWR-B Pressure limiters (with reclosing lockout), component tested for steam, hot water, burnable gases and liquid fuels Technical data Pressure connection External thread G A (pressure gauge connection) according to DIN 16 288 and internal thread G [ according to ISO 228 Part 1 (for gas applications internal thread permissible only up to 4bar). Switching device Stable housing (200) made of sea water resistant aluminium die casting. Materials Pressure bellows: Material No. 1.4571 Sensor housing: Material No. 1.4104 Switch housing: GD Al Si 12 (DIN 1725) Installation position Vertical and horizontal. Ambient temperature at the switching device 25 to 70 hc. Medium temperature 25 to 70 hc. The maximum medium temperature at the pressure sensor may at the most be equal to the permissible ambient temperature at the switching device. Briefly acting temperatures up to 85 hc are permissible. Higher medium temperatures are possible if the above limits at the switching device are ensured by suitable measures(e.g.waterpockettube). Installation Directly on the pressure line (pressure gauge connection) or on a level surface with2screws4mmdia. Switching pressure Adjustable from the outside by means of screwdriver. Bursting pressure For all types 100 bar, verified by TÜV test. Switching difference For values see type overview. Contacts Single-pole changeover switch. Switching capacity 250 V Ù 250V 24V (ohm) (ind) (ohm) (ohm) Normal 8A 5A 0.3A 8A Degree of protection IP 54 according to DIN 40 050 IP 65 (alternative version) Possibility of lead sealing On request (can also be fitted subsequently). Component tested for Steam Systems according to TRD 604 Hot water Systems according to DIN 4751, P. 2 Burnable gases DVGW work sheet G 260 Liquid fuels e. g. fuel oils Testing basis Registration No. Pressure 100/1, Issue 4.83 For max. pressure limiter: TÜV.SDB.97-310 For min. pressure limiter: TÜV.SDB.97-309 DIN 3398, P. 3, Issue 11.82 NG-4346 AQ 1411 DIN 3398, P. 4, Issue 10.86 3 C02 895 Function Direction of action Sensor Pressure limiter (with internal interlock) For max. pressure and min. pressure monitoring (SDBFS) Of special construction by test with 2 million switching cycles. The pressure limiters are equipped with a reclosing lockout for the mechanical interlocking of the switch-off state. If the switching point set on the pressure limiter is reached, the limiter switches off, the switch-off state is retained even if the pressure changes again. Switching back is possible only by manual actuation of the reset button. The pressure at the sensor must have lowered so that unlocking is possible (for maximum pressure limiters) or raised (for minimum pressure limiters). The values for the pressure change are listed in the type overview. Important: In the selection of the limiter, it is necessary to differentiate strictly whether the device is used for maximum or minimum pressure monitoring. It is not possible to reverse the direction of action at the pressure limiter. Maximum pressure limiters Type Setting Pressure Maximum operating Connection range change for pressure (bar) diagram unlocking 1* 2* DWR 06 205 0.1...0.6bar 0.06 DWR 1 205 0.2...1.6bar 0.09 DWR 3 205 0.2...2.5bar 0.20 DWR 6 205 0.5...6bar 0.30 DWR 625 205 0.5...6bar 0.50 DWR 16 205 3...16bar 0.70 DWR 25 205 4...25bar 1.4 DWR 40 205 8...40bar 2.3 Minimum pressure limiters DWR 06 206 0.1...0.6bar 0.06 DWR 1 206 0.2...1.6bar 0.09 DWR 3 206 0.2...2.5bar 0.20 DWR 6 206 0.5...6bar 0.30 DWR 625 206 0.5...6bar 0.50 DWR 16 206 3...16bar 0.70 DWR 25 206 4...25bar 1.4 DWR 40 206 8...40bar 2.3 6 6 10 16 20 25 50 63 6 6 10 16 20 25 50 63 TÜV DVGW * Maximum operating pressure and dimensions as for type series DWR. Pressure monitors DWR... (page 36) can also be used as minimum pressure and maximum pressure limiters with external interlock. Youwill findfurthermaximumpressurelimiterswithsafetysensor,typeseriessdbam..., on page 35. The types DWAM... can also be used with external interlock as maximum pressure limiters. 37
Technical data Type series DGM Pressure connection External thread G A according to DIN 16 288 and internal thread G [ according to ISO 228 Part 1 (permissible up to 4 bar). Switching device Sea water resistant aluminium die casting GD Al Si 12. Degree of protection IP 54, for vertical installation position. IP 65 (for EEx-d version). Materials of the pressure sensor see type overview. Ambient temperature 25 to +60 hc. 15 to +60 hc (for EEx-d versions). At ambient temperatures below 0 hc, ensure that no water condensation can arise in the sensor and in the switching device. Max. permissible operating pressure See type overview. Installation Either directly on the pipeline or with 2 screws 4 mm dia. on the wall surface. Installation position Vertical upwards or horizontal. In EEx-d version only vertical. Adjustment Continuously adjustable by means of screwdriver on the adjusting spindle. The set switching difference is visible in the scale window. Possibility of lead sealing On request (can also be fitted subsequently). Switching differences Largely independent of the set switching pressure. Not adjustable. For values see type overview. Adjustment Scale value corresponds to the upper switching point, the lower switching point is lower by the switching difference. Switching capacity 250 V Ù 250V 24V (ohm) (ind) (ohm) (ohm) Normal 8A 5A 0.3A 8A EEx-d 3A 2A 0.03A 3A Switching devices in EEx-i version with gold contacts. Max. switching capacity: 24 V DC 100 ma. Pressure measuring connection It must be ensured that a pressure measuring connection is available at a suitable place on the gas appliance. Pressure monitors, component tested for burnable gases also for applications Application Burnable gases according to DVGW work sheet G 260 Testing basis DIN 3398, P. 3, issue 11/82 Gas appliance directive 90/396 EEC Function Direction of action Pressure monitor, pressure limiter Pressure monitor (with internal or external interlock) For maximum pressure and minimum pressure monitoring DVGW Reg. No NG-4346 AP 1011 CE-Indent No. CE-0085 AQ 1088 Type overview Type Setting Switching Maximum Materials Dirange difference operating in contact men (Mean pressure with sional values) medium drawing DGM 306 A 15...60mbar 6mbar 0.8bar CU+Ms DGM 310 A 20... 100 mbar 7 mbar 0.8 bar CU + Ms 1 + 13 DGM 325 A 40... 250 mbar 10 mbar 0.8 bar CU + Ms DGM 06 A 100... 600 mbar 25 mbar 2 bar CU + Ms DGM 1 A 0.2...1.6bar 40mbar 3bar CU+Ms 1+14 DGM 506 15...60mbar 10mbar 5bar 1.4104 DGM 516 40... 160 mbar 12 mbar 5 bar 1.4104 1 + 12 DGM 525 100... 250 mbar 20 mbar 5 bar 1.4104 For further pressure ranges see type series DWR -versions Degree of protection EEx de IIC T 6, housing 700 Ex-DGM 506 15...60mbar 10mbar 5bar 1.4104 Ex-DGM 516 40... 160 mbar 12 mbar 5 bar 1.4104 3 + 12 Ex-DGM 525 100... 250 mbar 20 mbar 5 bar 1.4104 For further pressure ranges see type series DWR EEx-i version (intrinsically safe) Degree of protection EEx-ia, housing 300 DGM 306 513 15...60mbar 6mbar 0.8bar CU+Ms DGM 310 513 20... 100 mbar 7 mbar 0.8 bar CU + Ms 1 + 13 DGM 325 513 40... 250 mbar 10 mbar 0.8 bar CU + Ms DGM 06 513 100... 600 mbar 25 mbar 2 bar CU + Ms DGM 1 513 0.2...1.6bar 40mbar 3bar CU+Ms 1+14 DGM 506 513 15...60mbar 10mbar 5bar 1.4104 DGM 516 513 40... 160 mbar 12 mbar 5 bar 1.4104 1 + 12 DGM 525 513 100... 250 mbar 20 mbar 5 bar 1.4104 For further pressure ranges see type series DWR DVGW 38
Type series FD Maximum pressure limiter for liquid gas systems with safety function, Setting range 3 16 bar Technical data Pressure connection External thread G A (pressure gauge connection) according to DIN 16 288. Switching device (300) Die-cast aluminium GD Al Si 12. Type of protection IP 65 Explosion protection EEx ia (only when used in conjunction with Ex 041 isolating switching amplifier) Component testing See Summary of types Pressure sensing elements: Housing: 1.4104 Pressure bellows: 1.4571 All parts fully welded. Perbunan safety diaphragms (not in contact with medium) Ambient temperature 25 to +60 hc. For ambient temperatures below 0 hc it has to be seen that it is not possible to get condensation in the sensor and in the switching unit. Max. medium temperature 60 hc Outdoor Installations The pressure switch has to be protected against atmospheric influences. Max. permissible operating pressure 40 bar. Switching pressure: 3 16 bar Adjustable with adjuster spindle after removal of terminal box. Adjustment Safety pressure limiters break the control current circuit as pressure rises. The point at which reconnection takes place as pressure falls in lower by the amount of the switching differential. The scale value corresponds to the upper switching point. Fitting Can be fitted directly onto pressure line with suitable welding socket and union nut. Interlock after cutout Internal interlock on FD 16 327 Interlock defeat: after pressure reduction of approximately 2.5 bar by depressing the red key (with tool) on the scale side of the pressure switch. External interlock on FD 16 326 Interlock defeat: after pressure reduction of approximately 0.5 bar. Press defeat key in switch cabinet. Circuit break and short-circuit monitor On Types FD 16 326 and FD 16 327, in conjunction with Ex 041 isolating switching amplifier, the control circuit is monitored for short-circuit and circuit break. The resistor combination incorporated in the pressure switch ensures that a definite current flows at all times during normal operation. In the event of short-circuit or circuit break, the current level changes and the relay drops out to the safe side. TÜV t e s t e d The series FD pressure limiters are constructed in accordance with the special directives of liquid gas engineering. The requirements of TRB 801 Appendix II 12 are fulfilled. All parts of the sensor coming into contact with the medium are stainless steel 1.4104 and 1.4571. The parts of the sensor subjected to pressure are welded without filler metals. Over and above the requirements of the TRB, the pressure sensor is self-monitoring,i.e.intheeventofrupture of the pressure bellows, the pressure limiter switches off to the safe side. The pressure sensor thus complies with Special Design as defined in VdTÜV Code of Practice Pressure 100/1. The pressure limiters are operated in intrinsically safe control circuits (Explosionproof Protection EEx ia). When the Ex 041 isolating switching amplifier is used the control circuit is additionally monitored for circuit break and short-circuit. Type Overview Type Switching Inter- Peripherals TÜV testing station differential lock* identific. mark FD 16 326 0.5 E Isolating switching 09 91 0109 amplifier Ex 041, (self- FD 16 327 2.5 I monitoring), with circuit 09 91 0110 break and short-circuit monitor * Interlock on reaching to cutout point (maximum pressure set) Defeat E = External, i. e. in switch cabinet by relay with self-hold I = Internal, i. e. locally at pressure limiter For Technical Data of isolating switching amplifier, see Data Sheet Ex 041. Connection diagrams FD 16 326 Single-pole changeover switch with resistor combination for circuit break and short-circuit monitoring. (External interlock in switch cabinet necessary). FD 16 327 Single-pole changeover switch with mechanical switching state interlock on reaching maximum pressure and with resistor combination for circuit break and short-circuit monitoring. Important notice: Maximum pressure limiter never may be switched on to supply voltage. They only may be used in conjunction with Ex 041 isolating switching amplifier. 39
Type series DBS Pressure monitors and pressure limiters for high safety applications More safety x x in process engineering and chemical installations, in gas and liquefied gas installation Features Special construction according to VdTÜV Memorandum for pressure Druck 100/1 Line breakage and short circuit monitoring Suitable for Ex zone (zone 1 + 2) (type of protection against explosion EEx-ia) Type of protection: IP 65 Type specific features Self-monitoring sensor Positive opening microswitches Gold-plated contacts TÜV, DVGW component tests Options Plastic-coated housing Limiter with internal interlock Safety requirements of special construction The pressure limiters in safety function offer a high degree of safety compared with normal pressure switches and are therefore especially suitable for chemical process engineering and thermal installations in which special attention must be paid to safety. The pressure switches can also be used in Ex zones (zone 1 + 2) and in any event require a Ex 041 isolating switching amplifier. The isolating switching amplifier is also responsible for monitoring the lines for short circuit and line breakage and therefore offer an additional safety advantage even in non-ex zones. In the case of Ex applications, the isolating switching amplifier must be installed outside the Ex zone. The lines between the Ex 041 isolating switching amplifier and the pressure switch are monitored for short circuit and line breakage. Pressure limiters of special construction (SDB) fulfill additional safety requirements, i. e. breakage or leakage in the mechanical part of the sensor must lead to shutdown towards the safe side. Or the product type must have passed a test with 2 Mio switching cycles and have a stainless steel sensor. In the safe engineering consideration, the control circuit which runs through the pressure limiter must also be included, for short circuit in the supply lines or other faults in the control current circuit can lead to dangerous conditions. Switching element with positive opening operation and gold-plated contacts The microswitch is equipped with positive opening operation. In contrast to the transmission of the plunger force through a snap spring customary in most microswitches, the newly developed microswitch is provided with an additional lever which transmits the movements of the pressure bellows positively to the contact lever. If the snap spring breaks, the contact lever is moved directly. Wire breakage and short circuit monitoring with isolating switching amplifier Ex 041 The resistor connected in series to the switching contact limits the current to a defined value with the switch closed. In the case of short ciruit between the isolating amplifier and the series resistor, the current rises above the predetermined limit value, the relay of the isolating amplifier drops down, the output current circuit is interrupted and thus the assured condition is achieved. In the case of wire breakage, the current flow is interrupted, the relay drops to the safe side and interrupts the output current circuit (safety chain). The isolating amplifier is built so that in the case of faults in the electronics (conductor interruption, component defect etc.) and in the consequential faults resulting from this, the safe shutdown condition is assumed. This property of the isolating amplifier with safety function, including wire breakage and short circuit monitoring, is confirmed by the TÜV. It corresponds to the regulations of DIN/VDE 0660, Part 209. Connection diagram See also data sheet Ex 041 In pressure monitoring in Ex areas, the isolating amplifier must be installed outside the Ex-zone. An inherently safe control current circuit (EExia) is conducted through the pressure limiter. This arrangement is suitable for zone 1 + 2. Ex-Zone Pressure limiter Non Ex-Zone Isolating switching amplifier 40
Technical data Type series DBS Pressure connection External thread G A (pressure gauge connection) according to DIN 16 288. Switching device 500 Die-cast aluminium GD AI Si 12. On request: Aluminium housing chromated and coated with resistant plastic (Version 576 and 577). Type of protection IP 65. Ex protective category EEx-ia (only together with isolating switching amplifier Ex 041). TÜV testing office code Seepage41. Pressure sensor materials Housing: 1.4104 Pressure bellows: 1.4571 All parts completely welded. Ambient temperature 20 bis +60 hc. Al ambient temperatures around of below 0 hc, ensure that no condensed water can arise in the sensor and in the switchgear. Max. medium temperature +60 hc. Open-air systems Protect device against direct influence of weather. Provide suitable protective hood. Max. permissible operating pressure see type overview. Switching pressure setting Adjustable on setting spindle after removal of the terminal connection box. Adjustment The pressure limiters interrupt the control circuit with rising pressure. When the pressure drops they switch back at a lower pressure. The switching difference between the upper and lower switching point. The scale value corresponds to the upper switching point. Installation With suitable weld-on connections and union nuts or with pressure gauge screw union G. Switching element Seepage41. Switching power 24 V DC, max. 100 ma. (At higher switching power, the gold plating on the contact can be damaged). Connection Diagram Maximum pressure monitors for high safety applications Maximum pressure monitor Of special construction due to self-monitoring sensor. Type Adjustment range Switching differential Max. allowable (Mean value) pressure (bar) (bar) (bar) DWAM 06-576 0.1...0.6 0.04 5 DWAM 1-576 0.2...1.6 0.05 5 DWAM 2.5-576 0.4...2.5 0.07 5 DWAM 5-576 2...5 0.15 10 DWAM 625-576 1.2...6 0.25 20 DWAM 16-576 3...16 0.4 20 DWAM 32-576 6...32 1.2 45 Versions: ZF 577: Maximum pressure limiter with internal interlock (reclosing lockout) Microswitch not positive opening, contacts: silver alloy other equipment as for DWAM... 576 (chemical version) Ex 041 isolating switching amplifier, see page 48. Maximum pressure monitors Sensor of special construction due to component test with 2 million operating cycles (not self-monitoring). Type Adjustment range Switching Max. permissible pressure differential in other (mean values) gas media (bar) (bar) (bar) (bar) DWR 06-576 0.1...0.6 0.04 6 6 DWR 1-576 0.2...1.6 0.06 6 6 DWR 3-576 0.4...2.5 0.1 10 16 DWR 6-576 0.5...6.0 0.2 10 16 DWR 625-576 0.5...6.0 0.25 20 25 DWR 16-576 3.0... 16.0 0.5 20 25 DWR 25-576 4.0... 25.0 1.0 50 63 DWR 40-576 10.0... 40.0 1.3 50 63 Versions: ZF 577: Maximum pressure limiter with internal interlock (reclosing lockout) Microswitch not positive opening, contacts: silver alloy other equipment as for DWR... 576 EX 041 isolating switching amplifier, see page 48.... 576... 577 41
Technical data Type series DBS Adjustment The pressure limiters interrupt the control circuit on falling pressure. Switching back on rising pressure is higher by switching difference. The scale value corresponds to the lower switching point. Switching element See adjacent table Connection diagrams 2 3 2 3... 574... 575 The other technical data correspond to the devices for maximum pressure monitoring (page 41). Minimum pressure monitors for high safety applications Minimum pressure monitor in safety engineering Self-monitoring pressure sensor. Type Adjustment range Switching Max. permissible pressure difference for gas other (mean values) media (bar) (bar) (bar) (bar) DWR 06-574 0.1...0.6 0.04 6 6 DWR 1-574 0.2...1.6 0.06 6 6 DWR 3-574 0.4...2.5 0.1 10 16 DWR 6-574 0.5...6.0 0.2 10 16 DWR 625-574 0.5...6.0 0.25 20 25 DWR 16-574 3.0... 16.0 0.5 20 25 DWR 25-574 4.0... 25.0 1.0 50 63 DWR 40-574 10.0... 40.0 1.3 50 63 Versions: ZF 575: Minimum pressure limiter with internal interlock in chemical version Switching contacts: silver alloy Isolating switching amplifier Ex 041, see page 48. Equipment of the pressure monitors and pressure limiters in safety function Component tests 1 = VdTÜV Memorandum Pressure 100/1 2 = DIN 3398 Part.3 3 = DIN 3398 Part.4 Features Options Resistance combination for line break and short-circuit monitoring EExi equipment for intrinsically safe control circuits Self-monitoring Pressure sensor Positive opening microswitch Gold-plated contacts Limiter function with internal interlock (reclosing lockout) Housing plastic-coated, chemical version Maximum pressure monitoring FD 16-326 1 + 3 x x x x x FD 16-327 1 + 3 x x x x DWAM...576 1 x x x x x x DWAM...577 1 x x x x x DWR...576 1+2+3 x x x x x DWR...577 1+2+3 x x x x Minimum pressure monitoring DWR...574 1+2+3 x x x x x DWR...575 1+2+3 x x x x x 42
Dimensional drawings Pressure housings 1 Housing 200 (plug connection) 2 Housing 300 and 500 (terminal connection) 3 Housing 700 (Ex) 43
Dimensional drawings Pressure sensors 11 12 13 14 15 16 17 18 44
Type series DPS Technical data Pressure connection Plastic connection piece with 6 mm external diameter for measuring hose with 5 mm internal diameter. Connection piece P1 for higher pressure, P2 for lower pressure. Pressure medium Air, as well as non-combustible and non-aggressive gases Switching device Switch housing and pressure connection P2 made from PA 6.6. Lower part and pressure connection P1 made of POM Medium and ambient temperature 20 hc to+85hc (storage temperature 40 hc to+85hc) Maximum permissible operating pressure 50 mbar for all types Installation position Vertical, pressure connections below. (In horizontal installation position with the cover facing upwards, the scale values are20pabelowtheactualvalues,in horizontal installation with the cover facing downwards, the scale values are 20 Pa higher. Vertical installation is essential for set values below approx. 50 Pa!) Type of protection: IP 54 Installation By means of mounting pieces integrated in the housing with 2 screws directly onto a vertical surface, e.g. the air-conditioner or the air duct. In the case of installation in the ceiling area, use L brackets if necessary. Switching point adjustment Remove the cover and set the scale to the wanted value. The set values refer to the upper switching point (for maximum pressure monitoring). In the case of minimum pressure monitoring, the switching point is less than the set value by an amount corresponding to the switching differential. Weight: 160 g Switching function single-pole change-over Electrical connection Differential pressure switches for ventilation and air-conditioning Applications Differential pressure switch for filter, fan or air flow monitoring in air-conditioning and ventilation systems. Type overview Type Setting range Switching differential for upper switching pressure (standard values) (mbar) (mbar) DPS 200 F 0.2...2 0.1 DPS 400 F 0.4...4 0.2 DPS 1000 F 2...10 1 DPS 2500 F 5...25 1.5 Accessories supplied with the device: 2 m silicone hose, 2 connection pieces with mounting screws 2 self-tapping screws for mounting the housing 3 screw terminals for the electrical connection Optional accessory DPSL L bracket for installation turned by 90h, e. g. in the ceiling area. Dimensional drawing Use flat connector 6.3 x 0.8 DIN 46 244 or the screw terminals supplied. Switching capacity 1.5 (0.4) A/250 V AC Cable entry: Pg 11 Quotation text Differential pressure switch for filter, fan and/or air stream monitoring with adjustable scale. Switching capacity 1.5 (0.4) A at 250 V AC. With approvals according to VDE 0630 for 1.5 A and EN 1854 Max. operating pressure: 50 mbar; type of protection IP 54. Pressure and cable connections can be offset in different directions; including pressure connection accessories, consisting of 2 pressure connection pieces, 2 m silicone hose, 3 screw terminals for the electrical connection and mounting screws. 45
Technical data Type series HCD Pressure connection Pressure connection for overpressure: G [ internal tread. For vacuum and differential pressure: G 1 8, internal thread. Switching device Aluminium die-cast. Temperature of medium 15 up to +60 hc. Maximum admissible working pressure See summary of types. Installation position Horizontal with connecting piece pointing downwards Type of protection IP 40 according to DIN 40050. Mounting Either direct on pipe or with mounting bracket (is supplied as standard) onto a vertical surface. Adjustment of the switching point Remove cover and turn the setpoint spindle marked with +/ into the relevant direction. The scale indicates only standard values, for exact adjustment of the required value a manometer is necessary which can be connected at the measuring connection (pressure tapping piece 9 mm l). Electrical data Switching function Single pole switching over Electrical connection Pressure and Differential pressure switches for neutral gases (DVGW-tested) The pressure switches of series HCD are suitable for neutral and non-aggressive gases. They can be used for monitoring overpressure, vacuum and differential pressure. For detecting overpressure, connection is made on the pressure side at the lower connecting piece G[ for detecting the vacuum pressure at the upper connecting piece G 1 8 (remove locking clamp). For detecting the differential pressure, the high pressure is applied at the lower connecting piece (G[) and the low pressure at the upper connecting piece (G 1 8 ). For exact adjustment of the required value a pressure tapping (9 mm l) is available. The pressure switch is tested to DIN 3398 part 1 approved by DVGW for air and fuel gases to DVGW-standards G 260. It applies with the gas appliance directive 90 / 396 / EEC. Type Range of Switching diff. Max. adjustment (mbar) working (mbar) in in pressure (mbar) lower upper range range HCD 6003 0.2...3 0.3... 0.5 100 HCD 6010 1...10 0.3... 1 100 HCD 6050 5...50 1.5... 3 200 HCD 6150 15... 150 4... 10 300 The switching differential is not adjustable. The low switching differentials are valid for the lower range of adjustment, the higher values for the upper ranges. Dimensional drawings according to gas appliance directive 90 / 396 / EEC Positive pressure connection with [ ISO R 7 internal thread Pg 13.5 for cable entry Switching capacity 2 A/220 240 V AC (inductive load) 10 A/220 240 V AC (resistive load) Cable entry Pg 13.5 Mounting holes for bracket Cover screw Pressure adjusting screw high pressure inlet Venting or differential pressure connection 1 / 8 ISO R 7 internal thread 46
Type series EX 011 Isolating switching amplifier for intrinsically safe control circuits Features x 1-channel x Control circuit EEx-ia IIC x Reversible direction of action x 1 signal output with 1 change-over x EMCaccordingtoNAMURNE21 Application Suitable for all pressure and temperature switches with microswitches (basic versions) and for devices with the following additional functions (ZF):...V ZF301 ZF 203 ZF 213 ZF 205 ZF 513 ZF 206 Proximity switch (ZF 212, 312, 512) Microswitch Ex area Technical data Nominal voltage 230 V, 45 Hz... 65 Hz Power consumption: 1W Input (intrinsically safe) Terminals 1+, 3 Nominal data according to DIN 19 234 No-load voltage / short circuit current approx. DC 8 V / approx. 8 ma Switching point 1.2 ma... 2.1 ma Conformity certificate PTB No. Ex 94, C. 2086 Type of protection against explosion EEx-ia Outputs (not intrinsically safe) Contact loading AC: 250 V / 2 A / cos. > 0.7 DC: 240 V / 1 A ohmic load Switching frequency 10 Hz Galvanic separation Input/output according to DIN EN 50 020 safely galvanically separated. Input/mains according to DIN EN 50 020 safely galvanically separated. Output/mains according to DIN EN 50 178 Ambient temperature 20 hc...+60hc Direction of action The direction of action of the output can be adjusted with the slide switch S1 on the front of the housing. LED green = mains yellow = relay output red = line breakage Slide switches S 1 Direction of action S 2 Without function Installation Standard rail 35 mm Dimensions 20 x 115 x 93 (W x H x D) Switch position With the type EX 011 isolating switching amplifier, intrinsically safe control circuit commands can be transmitted to non-intrinsically safe active circuits. The inputs are separated safely from the outputs and from the mains according to DIN EN 50 178. In the intrinsically safe control circuit, both proximity switches according to DIN 19 234 and mechanical contacts can be connected. Direction of action You can adjust the direction of action of the outputs with the slide switch S 1 on the front of the housing. Control circuit Output relay LED yellow Switching contact closed X X Switching contact open X X The table applies for the switch position S 1 = OFF Type designation Output yellow red picked up on off dropped out off off Type Supply voltage Power consumption EX 011 230V, 45... 65 Hz 1W green Supply voltage 47
Type series EX 041 Isolating switching amplifier in safety technology for intrinsically safe control circuits for wire breakage and short circuit monitoring Features x 1-channel x Control circuit EEx-ia IIC x 1 safety-oriented relay output according to DIN VDE 0660 Part 209 (BIA Certificate No. 940 164) x 1 progressive output with 1 normally open contact x 1 passive electronic output, error message Application Suitable for all pressure monitors / pressure limiters in safety engineering with microswitches and resistance combination. ZF 576 ZF 574 ZF 577 ZF 575 Ex area red Pressure switch with resistance combination (for wire breakage monitoring) gelb yellow grün green Technical data Nominal voltage 230 V, 48 Hz...62 Hz Power consumption 3W Input (intrinsically safe) Terminals 10+, 12 No-load voltage / short circuit current approx. DC 8.4 V / approx. 11.7 ma Switching point Relay dropped out J < 2.1 ma and J > 5.9 ma Relay picked up 3.2 ma < J < 5mA Line resistance < 50 ohm. The cable capacitances and inductance must be taken into account in the Ex area. Conformity certificate PTB No. Ex 94, C. 2048 Type of protection against explosion, category EEx-ia Outputs (not intrinsically safe) Output I: (safety-oriented) Relay terminals 13, 14 Output II: (not safety-oriented) Relay terminals 15, 21 Contact load AC: 250 V / 1 A / cos. 0.7 DC: 24 V / 1 A ohmic load Output III Error message (not safety-oriented) Electronic output, passive, terminals 16+, 17 Nominal voltage DC 10 V...30 V Nominal current > 7 ma, short circuit-proof Switching frequency 5Hz Ambient temperature 20 hc...+60hc Installation Standard rail 35 mm Dimensions 40 x 115 x 93 (W x H x D) Output III The type EX 041 isolating switching amplifier is used for the transmission of intrinsically safe control commands (e. g. from pressure switches) to non-intrinsically safe active circuits. In the event of short circuit or line breakage in the control circuit, the isolating switching amplifier switches off to the safe side (see Direction of action Table). It also reacts towards the safe side (output relay dropped out) if internal component failures and resultant errors occur. Output I Relay output safety-oriented according to VDE 0660, Part 209, terminals brought to the outside separately for series connected protective interlock circuit, for instance. Output II Progressive output with relay stage (not safety-oriented) Output III Alarm output potential-free (not safety-oriented) Important note The type EX 041 isolating switching amplifier can be used only together with pressure switches with additional function ZF 576, ZF 577... (see also applications). Direction of action Control circuit Output relay Status Elektronic I and II indicator output III yellow red Switching contact closed X X Switching contact open X X Line breakage or short circuit in the input circuit Contact welding output I Output II Type designation Output I (acc. to VDE 0660, P. 209) picked up on off blocked dropped out off off blocked dropped out off on dropped out off on switched through switched through Type Supply voltage Power consumption EX 041 230V, 48... 62 Hz 3W Supply voltage 48
Technical data Type series FV-DS Material 1.4571. Version Completely assembled, evacuated, filled and adjusted. Filling medium M 20 (may be used for food applications) Temperatur range 40 hc...+300hc Max. permissible pressure 40 bar (applies only for separating membranes. The max. permissible pressure of the pressure switch must be observed.) Pressure mediators / separating membranes attached to pressure switches A separating membrane or a pressure mediator is necessary if aggressive, viscous or crystallizing media must be kept away from the actual pressure sensor. A pressure mediator is also indispensable to avoid cavities if easy cleaning of the supply lines is important. Special Milk pipe unions according to DIN 11 851 are customary for pressure monitoring in the foodstuffs industry. Pressure mediators and evaluating devices (pressure switches, pressure transmitters, pressure gauges) from a self-contained unit. The transmission fluid (filling medium) transmits the medium pressure from the separating membrane onto the measuring element. Type overview Flanged pressure mediators made of stainless steel 1.4571, membrane flush to the front, flange to DIN 2527 DN Pressure point from (bar) Temperature range* Type 50 0.3 40...120hC FV 184-50 80 0.15 FV 184-80 Flanged pressure mediators with 1 m pipeline, flange to DIN 2527 DN Pressure point from (bar) Temperature range* Type 50 0.3 30...300hC FV 185 N-50 80 0.15 FV 185 N-80 Pipeline up to max. 10 m on request. Pressure mediators for the foodstuffs industry with milk pipe connection according to DIN 11 851 DN Pressure point from (bar) Temperature range* Type 50 0.4 30... 120 hc FV 162-50 Screw-in pressure mediators flush to the front DN Pressure point from (bar) Temperature range* Type G1 0.6 30...120hC FV 749 * Please note that the temperature at the pressure switch must not exceed 60 hc continuously. 49
Accessories Siphons, NPT-adapter, pressure surge reducer, shutoff valves U-shape Siphons according to DIN 16282 made of seamless steal tube 20 mm l FORM B Material Type Inlet: Weld-on end with weld chamfer St 35.8-I U 430 B Outlet: Connection shank DIN 16 282 Form 6 1.4571 U 480 B G with clamping sleeve DIN 16 283 G FORM B Circular FORM D Material Type Inlet: Weld-on end with welding bevel St 35.8-I K 430 D Outlet: Connection shank DIN 16 282 Form 6 1.4571 K 480 D G with clamping sleeve DIN 16 283 G FORM D NPT adapter The purpose of the NPT adapter is to connect pressure switches, pressure transmitters, pressure gauges, etc., to NPT threaded connections. A suitable sealing washer is also supplied. Description Type NPT adapter, material 1.4104 and sealing ring NPT 1 DIN16258,FormCmaterialITCtoDIN3754P.1 Pressure surge reducer Material Ms Type DMW (water) 50
Accessories for differential pressure Male adaptor union G [HH /8mm G [HH external thread with O-ring seal for connection of pipes with 8 mm (± 0,1 mm) outside diameter. for adaption of: differential pressure switches DDCM... differential pressure transmitters FHBN... pressure switches / transmitters with G [ internal thread MAU 8 / Ms Type Overview body O-ring Type Brass NBR MAU 8 / Ms Stainless Steel 316 Ti (1.4571) FPM MAU 8 / Nst Max. permissible temperature: 100 hc Max. permissible pressure: 100 bar MAU 8 / Nst Valve combinations for differential pressure switches The valve blocks are suitable for differential pressure switches DDCM 014 to DDCM 16 and for differential pressure transmitter type series FHBN... Technical data Pressure stafe: PN 420 Materials: Housing 1.4404 internal parts 1.4571 Gaskets: Process connections: Scope of supply: PTFE 14NPT Complete with screw unions sharped pipe pieces in stainless steel. VKD 3 Type overview 3-fold combination VKD 3 5-fold combination VKD 5 The 5-fold combination contains 2 additional venting valves. The vale combinations are also available free of oil and grease on special request. VKD 5 51
SWW Flow monitoring in liquids and gases Technical data of the sensor General The flow sensor made of stainless steel 1.4571 is suitable for contaminated and with given material compatibility also for aggressive, fluid media. The flow in gaseous media can also be measured with this sensor. Medium temperature 0...80hC, higher medium temperatures (up to 120 hc) can cause switching point shifts; however, the sensor is not damaged. Temperature compensation up to 80 hc. Sensor material Parts in contact with medium 1.4571. Cable screw union nickel plated brass. Max. permissible pressure 20 bar. Connection thread G [. Connection cable four-core, 2.5 m long. Type of protection IP 65 max. 60 m shielded cable 4x1.5mm 2 ASW 454 SWF 62 The flow in fluids can be monitored reliably with the flow sensor SWF 62 and the evaluation unit ASW 454. The sensitivity can be adjusted accurately with a coarse and fine potentiometer. The switching state is indicated by LED. The sensor element must be located in the flow. Function The flow monitors work according to the calorimetric principle. A temperature-sensitive resistor is heated. Heat is withdrawn by the flowing air and the resistance changes. This resistance change is evaluated. Since the resistance value also depends upon the temperature of the medium, the difference must be compensated for by a second temperaturedependent resistor. The difference is compensated and thus the switching point is kept stable. Fast temperature changes may lead to switching when monitoring high flow speed. Technical data of the evaluation unit Operating voltage 230 V or 24 V AC/DC (see type overview) Power consumption approx. 3 VA Switching output Relay, single-pole changeover 8A,max.250VAC Ambient temperature 0 60 hc Max. temperature gradient 10 K/min. Sensitivity 0.1... 3 m/s (in fluid media) 1... 15 m/s (in gaseous media) Delay time 20 60 s Repeat accuracy < 2 %, related to the flow speed directly at the sensor Switching hysteresis Approx. 2 % full range. Max. cable length between sensor and evaluation unit 60 m, for shielded cable 1.5 mm 2 Probe breakage protection On breakage or interruption of the probe cables, the device is switched off or interruption of the flow is signalled. Type of construction Standard housing N 45. Weight approx. 0.35 kg Type overview Sensors Screw-in thread Type G [ SWF 62 Evaluation units Supply voltage Type User interface Setting elements Sensitivity (rough and fine for finetuning). Migh sensitivity for low switching point. Signal lamps 1 = Flow present 2 = Supply voltage present 230 V AC ASW 454 24 V AC/DC ASW 454/24 Connection diagram 52
SWL Airflow monitoring Sensor for air ducts, device for cabinet installation Technical data of the sensor General Fast reacting airflow sensor with adjustable flange for installation in air ducts. With temperature compensation, suitable for media with fast temperature changes. Medium temperature 20...+100hC Compensation behaviour (Speed of reaction to change of the medium temperature) fast, approx. 0.3 s Installation depth Adjustable up to 35 mm Diameter of the probe tube 10 mm Sensor material Nickel plated brass Measuring element Insensitive to humidity (cleaning in water is possible). Sensitive to mechanical bending (take care when cleaning with hard objects). Type of protection IP 32 Electrical connection Terminal block accessible after removing the cover. 3-core connection to the evaluation unit. Cable entry Pg 11 ASL 453 max. 100 m shielded cable 3x1.5mm 2 SLF 3 The combination of airflow sensor (type SLF 3) and evaluation unit (type ASL...) is suitable for airflow monitoring in air-conditioning systems, ventilation and cooling systems and wherever flow processes in air or neutral gases have to be detected. The sensitivity can be adjusted within wide limits. Function The airflow monitors work according to the calorimetric principle. A temperature-sensitive resistor is heated. Heat is withdrawn by the flowing air and the resistance changes. This resistance change is evaluated. Since the resistance value also depends upon the temperature of the medium, the difference is compensated for by a second temperature-dependent resistor. The difference is compensated and thus the switching point is kept stable. Technical data of the evaluation unit Operating voltage 230 V or 24 V AC/DC (see type overview) Power consumption approx. 3 VA Switching output Relay, single-pole changeover 8A,max.250VAC Ambient temperature 0 60 hc Sensitivity Adjustable 0.1... 20 m/s for gaseous media Delay time < 1s Repeat accuracy < 2 %, related to the flow speed directly at the sensor. Switching hysteresis approx. 2 % of the total range. Max. cable length between sensor and evaluation unit 100 m, for shielded cable 1.5 mm 2 Probe breakage protection On breakage or interruption of the probe cables, the device is switched off or interruption of the flow is signalled. Type of construction Standard housing N 45 Weight approx. 0.35 kg Switch-on bypass While the plant is being started up (still no airflow present), the output contact is activated and the flow condition signalled. The time for the switch-on bypass is adjustable from 2 60 s. The starting or switch-on bypass starts when switching the device on. With external connection (terminals Z-Z) with a start button (normally closed contact), the starting bypass starts with actuation of the button (locking). Type overview Supply voltage Type Sensor SLF 3 Evaluation unit 230 V AC ASL 453 User interface Setting elements s = Sensitivity t = Time for switch-on bypass 24 V AC/DC ASL 453/24 Connection diagram Signal lamps 1 = Flow present or switch-on bypass active 2 = Supply voltage present brown black blue G with locking button 53
Quotation Text Pressure Switches Series Series DCM... Pressure switch with plug connection to DIN 43650. Switching housing of aluminium die casting GD Al Si 12, type of protection IP 54. Range of adjustment... to... bar/mbar. Switching differential adjustable / not adjustable. Pressure connection G, internal thread G[. Type: DCM... DNM.../ VNM... DNS.../ VNS... DNS...351/ VNS...351 DDCM 252... DDCM 6002 DDCM 1... DDCM 16 DWAM.../ DWAMV... Pressure switch with plug connection to DIN 43650. Sensor casing of high grade steel 1.4104. Switching housing of aluminium die casting GD Al Si 12, type of protection IP 54. Range of adjustment... to... bar/mbar. Switching differential adjustable / not adjustable. Pressure connection G, internal thread G[. Type: DNM..., VNM... Pressure switch with plug connection to DIN 43650. Sensor complete of high grade steel 1.4571. Switching housing of aluminium die casting GD Al Si 12, type of protection IP 54. Range of adjustment... to... bar/mbar. Switching differential adjustable / not adjustable. Pressure connection G, internal thread G[. Type: DNS..., VNS... Pressure switch with terminal connection. Sensor complete of high grade steel 1.4571. Switching housing of aluminium die casting GD Al Si 12, housing with surface protection, type of protection IP 65. Range of adjustment... to... bar/mbar. Switching differential adjustable / not adjustable. Pressure connection G, internal thread G[. Type: DNS..., VNS... Differential pressure monitor with plug connection to DIN 43650. Sensor casing of aluminium, diaphragm of perbunan. Pressure connection G[, internal. Switching housing of aluminium die casting GD Al Si 12, type of protection IP 54. Range of adjustment... to... bar/mbar. Type DDCM... Differential pressure monitor with plug connection to DIN 43650. Senosr of high grade steel 1.4104 and 1.4571. Pressure connection G[, internal. Switching housing of aluminium die casting GD Al Si 12, type of protection IP 54. Range of adjustment... to... bar/mbar. Type: DDCM... Pressure monitor of special construction for maximum pressure monitoring with self-monitoring sensor (safety sensor). Tested according VdTÜV-Memorandum DRUCK 100/1. Switching housing of aluminium die casting GD Al Si 12, plug connection to DIN 43650, type of protection IP 54. Range of adjustment... to... bar/mbar. Switching differential adjustable / not adjustable. Pressure connection G, internal thread G[. Type: DWAM... SDBAM... DWR.../ DWR...203 DWR...205/ DWR...206 DGM... DWAM...576 Pressure limiter of special construction for maximum pressure monitoring. With internal interlock (reclosing lockout) with self-monitoring sensor (safety sensor), tested according VdTÜV-Memorandum DRUCK 100/1. Switching housing of aluminium die casting GD Al Si 12, plug connection to DIN 43650, type of protection IP 54. Range of adjustment... to... bar/mbar. Pressure connection G, internal thread G[. Type: SDBAM... Pressure monitor of special construction for maximum pressure monitoring and minimum pressure monitoring. Tested according VdTÜV-Memorandum DRUCK 100/1 as well as DIN 3398, p. 3 and p. 4. Switching housing of aluminium die casting GD Al Si 12, plug connection to DIN 43650, type of protection IP 54. Range of adjustment... to... bar/mbar. Switching differential adjustable / not adjustable. Pressure connection G, internal thread G[. Type: DWR... Pressure limiter of special construction for maximum pressure monitoring (205) or minimum pressure monitoring (206). Interlocking of the switch-off state (reclosing lockout). Tested according VdTÜV-Memorandum DRUCK 100/1 as well as DIN 3398, p. 3 and p. 4. Switching housing of aluminium die casting GD Al Si 12, plug connection to DIN 43650, type of protection IP 54. Range of adjustment... to... bar/mbar. Switching differential adjustable / not adjustable. Pressure connection G, internal thread G[. Type: DWR... Pressure monitor for gas with plug connection to DIN 43650. DVGW-tested according DIN 3398, p. 1 and p. 3. Sensor casing of Cu/Zn/high grade steel 1.4104. Switching housing of aluminium die casting GD Al Si 12, plug connection to DIN 43650, type of protection IP 54. Range of adjustment... to... bar/mbar. Switching differential adjustable / not adjustable. Pressure connection G, internal thread G[. Type: DGM... Pressure monitor of special construction for maximum pressure monitoring. With self-monitoring sensor (safety sensor), positive opening microswitches (gold-plated). Resistor combination for wire breakage and circuit monitoring. Tested according VdTÜV-Memorandum DRUCK 100/1. Switching housing of GD Al Si 12, type of protection IP 65. Range of adjustment... to... bar/mbar. Pressure connection G, internal thread G[. Type: DWAM...526. 54
Quotation Text Pressure Switches / Isolating switching amplifier / Flow monitoring Series Pressure switch Series Isolating switching amplifier FD 16 326 FD 16 327 Pressure monitor of special construction for maximum pressure monitoring in liquid gas systems with self-monitoring sensor (safety-sensor). Resistor combination for wire breakage and circuit monitoring. Tested according VdTÜV-Memorandum DRUCK 100/1 and DIN 3398, p. 4. Explosion protection: EEx-i. Switching housing of GD Al Si 12, type of protection IP 65. Adjustablefrom3to16bar. Pressure connection G and G[ internal. Type: FD 16 326. Pressure monitor of special construction for maximum pressure monitoring in liquid gas systems with self-monitoring sensor (safety-sensor). Switching state interlock. Resistor combination for wire breakage and circuit monitoring. Tested according VdTÜV-Memorandum DRUCK 100/1 and DIN 3398, p. 4. Switching housing of GD Al Si 12, type of protection IP 65. Adjustablefrom3to16bar. Pressure connection G and G[ internal. Type: FD 16-327. Ex 011 Ex 041 Series SWF 62 ASW 454 Isolating switching amplifier for intrinsically safe control circuits. Type of protection against explosion: EEx-ia. Signal output: 1 change-over. Nominal voltage: 230 V, 45 60 Hz. Type: Ex 011. Isolating switching amplifier in safety technology for intrinsically safe control circuits. Type of protection against explosion: EEx-ia. Signal output: safety-oriented relay output. Nominal voltage: 230 V, 45 60 Hz, type of protection IP 65. Type: Ex 041. Flow monitoring Flow sensor for liquids, screw in thread G[, parts in contact with medium 1.4571. Max. permissible pressure 20 bar, connection cable 2.5 m. Type SWF 62. Together with Evaluation unit for flow sensor SWF 62 in standard housing N45, with integrated probe breakage protection. Signal output: relais 8 A, max. 250 V. Supply voltage: 230 V AC (type ASW 454) or 24 V AC/DC (type ASW 454/24). SLF 3 Airflow sensor for air ducts. Type SLF 3. Together with ASL 453 Evaluation unit air flow sensor SLF 3 in standard housing N45, with integrated probe breakage protection. Signal output: relais 8 A, max. 250 V. Supply voltage 230 V AC (type ASL 453) or 24 V AC/DC (type ASL 453/24). 55
Pressure Switches with safety certificates for steam, hot water, gas and oil for e applications for industrial applications for vacuum for differential pressure Fema Controls Honeywell AG P. O. box 12 54 71099 Schönaich / Germany Phone ++49 (0) 70 31 / 637-02 Fax ++49 (0) 70 31 / 637-850 email fema@honeywell.com www.honeywell.de/fema H f Technical data and pictures not obligatoryfor delivery. Subject to change. EN3B0268GE51 R1000