7 221 Pressure Switches QPL... The pressure switches are used for monitoring gas or air pressures. When the pressure falls below the switching point, the associated electrical circuit will open or switch over. The QPL... and this Data Sheet are intended for use by OEMs which integrate the pressure switches in their products. Use The QPL... are pressure switches for minimum pressure. The pressure ranges cover pressures from 1.5 to 280 mbar. 25.03.2003 HVAC Products
Warning notes To avoid injury to persons, damage to property or the environment, the following warning notes should be observed! Do not open, interfere with or modify the pressure switch! Before performing any wiring changes in the connection area of the switch, completely isolate the equipment from the mains supply (all-polar disconnection) Ensure protection against electric shock hazard by providing adequate protection for the connection terminals Check to ensure that wiring is in an orderly state Fall or shock can adversely affect the safety functions. Such units may not be put into operation, even if they do not exhibit any damage Do not use the pressure switch in inflammable or explosive gas atmospheres Engineering notes Setting the switching point To set the required switching point, remove the cover of the pressure switch and turn the setting knob clockwise to increase the set value, and counterclockwise to decrease it (see scale in Fig. 7221m01 under «Dimensions»). Replace cover and tighten the 2 screws to prevent tampering. Mounting notes Ensure that the relevant national safety regulations are complied with Check piping connections and housing of the pressure switch to ensure that there are no leaks The pressure switch can be mounted either horizontally or vertically The pressure switch can be connected via a ¼ thread or O-ring, depending on the type of switch (refer to Figs 7221z01 and 7221z04 below) Connection via ¼ thread Connection via O-ring QPL1... O-ring Fixing screws M4 7221z04e/0702 Spacers 2/6
Installation notes Installation work must be carried out by qualified staff Commissioning notes Commissioning work must be carried out by qualified staff Prior to commissioning, ensure that wiring is in an orderly state Norms and standards Conformity to EEC directives - Electromagnetic compatibility EMC (immunity) 89 / 336 EEC - Directive for gas-fired appliances 90 / 396 EEC - Pressure sensing devices for gas burners and gas-fired appliances EN 1854 (CE 0063 BL 1455) Service notes Maintenance work must be carried out by qualified staff Each time a pressure switch has been replaced, check to ensure that wiring is in an orderly state Disposal notes The unit contains electrical and electronic components and may not be disposed of together with household waste. Local and currently valid legislation must be observed. Mechanical design - Housing made of durable plastic with die-cast aluminium base - Adjustable switching point - Automatic reset manual reset on request The pressure switch can be adjusted within the respective pressure range indicated by the scale at the top. The QPL... comes calibrated and has been checked for leaks. 3/6
Type code Q P L 1 2. 0 5 0 A 0 0 Customer-specific version Reset A M Automatically Manually (on request) Pressure range 010 up to 10 mbar 050 up to 50 mbar 075 up to 75 mbar 090 up to 90 mbar 140 up to 140 mbar 150 up to 150 mbar 280 up to 280 mbar Electrical connection 1 Hole for 1/2" NPSM connector (standard) 2 4-pin DIN 43650 plug-in base 3 Watertight connection 1/2" (on request) 7221t01e/0303 Mounting 1 O-ring 2 ISO thread 1/4" 3 NPT 1/4" thread (on request) Switching action L Switches when pressure falls below the set value H Switches when pressure exceeds the set value (on request) Type summary Pressure switches with automatic reset. Pressure switches for minimum pressure Pressure range ¼ connection O-ring connection 1.5...10 mbar QPL22.010A00 QPL12.010A00 2.5...50 mbar QPL22.050A00 QPL12.050A00 12.5...75 mbar QPL22.075A00 ¹) QPL12.075A00 ¹) 70...280 mbar QPL22.280A00 QPL12.280A00 ¹) On request Ordering When ordering, please give type reference according to «Type summary». 4/6
Technical data General data Switching voltage Switching current Adjustable operating pressure Pressure surge Operating pressure Operating pressure (continuously) Weight Low-pressure range Mounting position Safety class Degree of protection Deviation of switching point Typical hysteresis: Type reference Deviation switching point QPLxx.010 0.5 mbar QPLxx.050 1 mbar QPLxx.075 3 mbar QPLxx.280 5 mbar DC / ACeff max. 250 V ACeff max. 10 A (at cos 1 lamp load) ACeff max. 2 A DC max. 0.25 A ACeff min. 20 ma DC min. 20 ma 1.5... 280 mbar (different ranges) 1 bar for 2 s max. 600 mbar for max. 30 s 400 mbar approx. 225 g refer to «Type summary» horizontal or vertical II IP 40 (to be ensured through adequate mounting) ±15 %, referred to the setpoint (diaphragm in vertical position) Environmental conditions Transport DIN EN 60 721-3-2 Climatic conditions class 2K2 Mechanical conditions class 2M2 Temperature range -40...+60 C Humidity < 95 % r.h. Operation DIN EN 60 721-3-3 Climatic conditions class 3K5 Mechanical conditions class 3M2 Temperature range -20...+60 C Humidity < 95 % r.h. Condensation, formation of ice and ingress of water are not permitted! Function With automatic reset. Pressure switches for minimum pressure Switch opens the electrical circuit when the air or gas pressure falls below the set value. 5/6
Connection diagram 3 COM P 2 1 NO NC 7221d01/0702 Pressure switch QPL... for minimum pressure When pressure falls below the set value: NO opens, NC closes Connection via connector to DIN 43650 Dimensions Dimensions in mm Connector to DIN 43650 76.2 Pressure adjustment 22.22 Standard SIEMENS LANDIS & STAEFA 7221m01e/0303 76.2 67.8 Setting range 1/4" N.P.T. (ISO) Pressure connection only QPL2... 21.3 6/6 2003 Subject to change!