Energy Conversions Inc.

Transcription

1 Energy Conversions Inc. Maintenance and Operation Manual Economizer Dual Fuel Conversions System GE Locomotives Energy Conversions Inc Pacific Hwy. East, Tacoma WA Phone: , Fax Web: Second edition October 2008 Energy Conversions Inc. all rights reserved

2 Table of Contents Gas Safety Properties of Natural Gas Inspection of Gas Piping and Hoses Precautions during Gas Fuel System Maintenance. 3 System Overview and Description Economizer Gas Fuel Supply Hardware Operation Sensors ECU Touch Screen ECU Screen Acronyms ECU Touch Screen Flow Menu ECU Touch Screen Flow Menu Engine Operating Procedures Flexible Hoses between Locomotive and Fuel Car Connecting the Fuel Car Hoses Disconnecting the Fuel Car Hoses Service and Maintenance Detail Information Trouble Shooting

3 Gas Safety Natural gas is safe as any fuel, including gasoline or diesel. But, like other fuels, it has properties that require special handling consideration. For your safety and others, please read and understand the following natural gas information and fuel handling precautions. Properties of Natural Gas Natural gas consists mostly (>90%) of methane: a colorless, odorless, nontoxic gas. The familiar odor of gas is not the gas itself, but a pungent additive called methyl mercaptan. If the converted engine is using pipeline gas mercaptan has probably been added and you will be able to smell gas leaks. However, if your source of fuel is liquefied natural gas (LNG), you may not be able to smell gas leaks. This is because mercaptan is usually not added to LNG. Therefore, don t rely only on your nose to detect gas leaks. Use the procedures outlined in the manual for checking the integrity of gas line connections and joints. Natural gas will not burn unless it is mixed with between 85% and 95% air by volume. Natural gas, like helium, rises in air. These two facts mean that as long as there is adequate ventilation in the vicinity of the converted engine and gas fuel supply there is little danger of fire. A problem can arise however when natural gas is allowed to accumulate in closed areas without ventilation. Accumulated natural gas can be very dangerous. Therefore, always maintain adequate ventilation in the area of the converted engine and fuel supply. Inspection of Gas Piping and Hoses Gas piping and hoses should be inspected on a quarterly basis. Engine gas pipe inspection should be performed with engine running on gas, spray soapy water on all piping joints, mating connections. Bubbles forming will indicate leaks. Inspect gas vent at regulator or the discharge hose. Gas should not be venting while engine is operating on gas or on diesel. Precautions during Gas Fuel System Maintenance Before working on the gas system first locate the manual gas shut-off valve and turn to off position, the location of shut off valves varies per application. Some locomotives they will be at each end of the locomotive as well as by the engine. For applications storing high pressure gas, consider closing the high pressure supply and venting the trapped pressurized gas if necessary. Also, when working around any fuel, remember to remove or shut off all possible ignition sources before working on the gas fuel system including lighted cigarettes, welders, portable 3

4 generators, kerosene heaters, electric motors, or anything else that could generate sparks or flame. Manual Gas Shut-Off Valve Manual Gas Shut-Off Valve Handle in the CLOSED Position Manual Gas Shut-Off Valve Handle in the OPEN Position 4

5 System Overview and Description The ECI Economizer Dual Fuel System is a retrofit technology that allows diesel engines to operate on a mixture of diesel fuel and natural gas. The conversion system is designed for ease of installation and reliability with no major changes or modification to the engine. After the conversion the engine still has the ability to operate in 100 percent diesel fuel mode. The dual fuel system has been designed to allow for switching of fuel modes during full or part load conditions, without interruption in engine speed, power, or stability. The system utilizes a fumigation gas delivery method whereby gas is delivered to the cylinders via the standard engine air-intake system. The gas is ignited in the combustion chamber by a diesel pilot, which acts as an ignition source for the air gas mixture. The dual fuel control system monitors various engine and system parameters such as; intake manifold air pressure and temperature, exhaust gas temperature, engine speed, engine load, gas pressure, and engine vibration. This information allows the Economizer Control Unit (ECU) to automatically activate or deactivate the dual-fuel operation. The Economizer Control Unit is also designed with fail-safe features. If a problem or malfunction is detected, the ECU instantly and automatically deactivates the dual fuel mode and switches the engine transparently to 100 percent diesel fuel operation mode. 5

6 Economizer Gas Fuel Supply Hardware The gas fuel supply hardware consists of storage tanks, Pressure Reducing Skid and connection hoses and fittings on the fuel car. Locomotive has a manual gas shut off valve, Automated Locomotive Shutoff Valves, gas pressure regulator, a Gas Cut Off Valve, Gas Flow Control Valve, piping and flexible gas hose, and further downstream is the gas diffuser. Operation Under normal operation, gas is supplied to the system at a nominal 25 psi. The pressurized gas passes through the opened manual gas valve through the Locomotive Shut Off valves, Regulator and filter. The regulator is designed to maintain its pressure setting downstream even when upstream pressure changes. The gas pressure is stopped at the Gas Cut Off Valve (GCOV). The GCOV is pneumatically operated and is controlled by the Engine Control Unit (ECU). When the ECU determines that it is time for gas operation, it opens the GCOV, allowing gas to flow to the Gas Flow Control Valve (GFCV) where the gas amount is controlled to meet the engine power requirement. 6

7 Sensors Sensors are used to create electrical signals proportional to the process variable they are designed to measure. The electrical signals are measured by the Engine Control Unit (ECU) and converted to engineering units or real world numbers. The conversion system controller measures the following process variables: Air Manifold Pressure Air Manifold Temperature Barometric Pressure Exhaust Gas Temperature Flywheel Speed Gas Pressure Governor Position (application specific) Jack Water Temperature Power by Volts and Amps Knock Sensor The sensors are very important components to the conversion system. It is critical that they are in good working order if the conversion system is to operate properly. The ECU uses the information to determine if gas operation can be performed and to tune engine performance. In nearly all cases a bad sensor will result in not being able to operate in the gas mode. 7

8 ECU Touch Screen The display touch screen on the ECU is the window into the operation of the Economizer System. The screen uses rectangular touch buttons to navigate to various information screens. The Home Screen indicates the power output of the running engine, gas flow and whether or not the system is ready to operate with gas. Indication on or off of gas is made known by screen color. If the screen is green, the engine is running on gas. If the screen is orange the engine is running on diesel. Screen color changing is done the same time as the GCOV valve function changes. Some factors provide instant shut-off and some factors provide for a 5- second ramping off of gas. So the screen color change may be delayed from the time you flick the switch. By pressing the menu button on the home screen you gain access to 12 sub screen options. If the screen indicates the unit is not on gas, Menu1 provides a Limit and Limit2 buttons for access to possible out of limit values. By selecting one of these two buttons 16 factors can be displayed. The factor that caused the unit not to use gas will be blackened, allowing for troubleshooting. Most of these blackened buttons can be touched to access further information. There are 3 factors that will cause a Latched Fault (LF). A Latched Fault is where the fault will not automatically reset itself with a good value. Excessive knock signal will lock the system onto diesel, high gas pressure, or high engine speed after the programmed number of retries (typically 5) will require you to reset the latch. Turn the ECU mode switch off and on again to reset. The system includes a clock that is used to time stamp the most recent Out Of Limit message. This is useful for a quick check that the unit has been running without any recent Out Of Limit conditions. This information is accessed from the Menu1 screen Last Limit. The Last Limit message is reset anytime the system is powered off and a fault message is only set when it is automatically switched from gas to diesel. The clock is also used to record the amount of time the engine is running as well as the time it has run with gas. This information is accessed from Menu2. The clock is only adjustable through a PC with time adjustment program. 8

9 ECU Screen Acronyms (Meanings and Normal Limit Settings) Limit levels are set for most of the system variables to suit each engine family and type. Differences in RPM and Power levels are common and specific to generator type. Values outside of normal limits and levels will cause the system to operate in the diesel mode. Not all of these values are pertinent to every application. Altcomp = Altitude compensation Amp = Air Manifold Pressure, 0-20 psi is common, some applications can have upper levels of 30. AmT = Air Manifold Temperature, 80 F to 250 F. depending on after-cooler arrangements Ampc =Pressure compensation Amtc = Temperature compensation Baro = Barometric Pressure, Hg. Calib = Calibration Delta = Difference between set point and actual governor position, a unit-less number that is normally within +/- 200 Drive % = Percent of Pulse width drive to GFCV, EGT = Exhaust Gas Temperature F changing with load and air temperature GPE = Gas Pressure Engine, typically 35 WC, WC GPM = Gas Pressure Meter, meter compensation measurement PSI GT = Gas Temperature, F HP = Horse Power, percent of generator rating I/O = On/Off Switch JWT = Jack Water Temperature, F KNO = Knock, unit-less number makes fuel adjustments above the number 75 LDS = Leak Detection System, this on off signal tells the system if all is good LF = Latched Fault, turn mode switch off and on to reset MGA = Main Generator Amps, (Locomotive dependent) MGV = Main Generator Volts, RPM = Engine Speed, +/- 10 percent of operating speed with some exceptions V0 = Trim adjustment, percentage of reduced gas setting 9

10 ECU Touch Screen Flow Menu1 Menu Screen Menu1 Screen Menu1 Pressure Menu1 Temperature Menu1 Trims Menu1 Limits Menu1 Limit2 Described above are the most common screen configurations. Small changes and differences may be found with your system depending on particular custom modifications. 10

11 ECU Touch Screen Flow Menu2 Home Screen Menu2 Screen Menu2 Fuel Menu2 Erpm Menu2 Calib Menu2 Clock Menu2 Outval Menu2 Trims 11

12 Engine Operating Procedures Operation with dual fuel is identical to the operation of standard diesel engine. The dual fuel engine is started as regular diesel engine on diesel with normal procedures. To run engine in the dual fuel mode the operator will need to open the manual gas valves and set the mode switch on the side of the ECU to the up position, gas mode. These two procedures can be done at anytime before or after the engine has been started. Once the engine reaches desirable operating temperature and load conditions, the dual fuel system operation commences automatically with no operator input required. If a function falls out of normal operational limits, full diesel operation is resumed instantly and seamlessly, with no interruption of service. Procedures to Run Locomotive on Gas 1. Verify that the flexible connecting hoses between the locomotive and the fuel tender car are connected. Small air hose, large gas hose, two medium water hoses. 2. Verify that the gas vent valve is closed and the manual shutoff valves are in the open position. 3. Verify that CNG high pressure valve on fuel car is open. 4. Verify that there are no water or gas leaks. 5. Mode switch up, on the side of the ECU box. If all the hoses and valves are open and the engine is running the screen should indicate READY or Operative When all procedures listed in above are completed, the locomotive is ready to run on CNG. The locomotive engine must be at its normal operating temperature and gas pressure in normal limits. Gas operation will occur when engine is producing power at throttle notch three. Flexible Hoses between Locomotive & Fuel Car The locomotive is connected to the CNG storage car with four flexible hoses. The largest hose is for the gas from the CNG storage car, two medium hoses carry the heated engine water from the locomotive to heat exchanger on the pressure reducing skid where it 12

13 warms the gas, cooled from expansion. The small hose is controlled air pressure that turns the gas on as long as system parameters are in order. Connecting the Fuel Car Hoses The hoses can be connected to the locomotive when the engine is running or not. Don t try it when engine is above idle. Assuming that all the manual valves are off Always be sure that the locomotive is securely coupled to the fuel car before connecting hoses, always be sure others are aware you are connecting, and that nobody will move the locomotive while you are making connections. 1. Open vent valves on the gas line to be sure there is no trapped, pressurized gas, then close the vent valves. 2. Be sure to keep the fittings clean and free of dirt. Connect the gas hose by starting the coupling together, pull the sleeve back to release the quick coupling and push it further onto the mating fittings pilot. Once started it is not necessary to continue holding the ring back. Keep aligned and give it a shove to compress the check valve springs and latch the connector. Be sure the sleeve securely latches and the coupling is fully connected. Open the manual gas valves 3. Connect the water hoses in the same manner as the gas hose. Connect the air hose. Open the manual valves. 4. If not already done, open the high pressure gas supply valve slowly. 5. Check the hoses for leaks. Disconnecting the Fuel Car Hoses 1. Always disconnect the hoses before releasing the car coupling 2. Close the manual gas shut off valves both on the locomotive and on the fuel car. Open one of the gas vent valves and let the gas pressure out. 3. Close the vent valve. 4. Disconnect the four hoses in any order you like by pulling the release sleeve and pulling on the hose. Take care not to damage the fittings, don t let the disconnected fittings bang onto the car coupling or frame, and try not to twist or kink the hoses. Try to keep the hose ends out of the dirt. (NOTE: If it is expected that service work is to be done to the fuel car then you should vent the complete system by first shutting the high pressure valve, venting the gas with the manual valves open.) 13

14 Service and Maintenance Initially the conversion system should be monitored quite regular, recording the operational time clocks and making sure that the operation is mostly with gas. If time clocks indicate that excessive diesel operation occurs then it will be necessary to determine the cause. Eventually the conversion system should be inspected for proper operation every 90 days. A load test operating with gas will cause all of the devices to be functional. If load testing is not practical then at least a short ride with the unit working on gas should be performed for making the necessary tests for gas operation. Cab indicator trouble lights will light when the gas system determines something is not normal. Information from the operating crews should normally indicate that the trouble lights are rarely on. Gas operation lights should indicate operation when in the upper throttle notches. Daily Tasks added to normal service tasks: WHAT WHO HOW COMMENTS Operation Engineers Visual indicators Check to see that the fault light is usually not on. Green light is usually on above notch 2 Hoses and pipes Engineers Visual inspect for damage or leaks Leak Detection System Engineers Visual inspection of LDS panel General inspection to insure that pipes and hoses are in good working order Check to be sure that all four sensors are good and no leak lights are lit. At first, weekly then monthly, finally every 90 days after weekly operations prove good: WHAT WHO HOW COMMENTS Operation Manager Talk to engineers Make sure locomotive operation is satisfactory with gas operation. High pressure filter Maintenance See below on filter inspection. Pipes and hoses Maintenance Visual and soapy water Check pipes for leaks Leak Detection System Maintenance Visual Check to be sure that all four sensors are good and no leak lights are lit. 14

15 Every 90 Days: WHAT WHO HOW COMMENTS Operation Manager Talk to engineers Make sure locomotive operation is satisfactory with gas operation High pressure filter Maintenance See below on filter inspection. Pipes and hoses Maintenance Visual and soapy Check pipes for leaks. water Regulator vents Maintenance Feel and soapy water Make sure gas is not escaping from regulator vent. Leak Detection System Maintenance Visual Check to be sure that all four sensors are good and no leak lights are lit. Testing Maintenance Load testing Operationally test the unit to confirm proper gas operation. Knock system Maintenance Laptop connection Inspect the input channels to determine that the sensors are good and signals are coming in. See Detail Information for explanation. Differential Pressure Transducer Maintenance Visual Inspect for near 0 reading at no gas flow conditions (0 error in excess +/- 1) Gas piping should be checked for leaks using soapy water when the system has pressure on it (check gas pressure on system information screen). Visually inspect hoses and piping for leaks or damage. High Pressure Filter on Pressure Reducing Skid (with CNG fuel storage): Close the high pressure supply valve, locate vent valve and drain gas pressure off of the skid. Carefully remove the plug on bottom of filter canister. Drain any accumulated liquids. Note the volume and consider when the next inspection period should be. After approximately 6 months of operation, vent as above, then carefully remove filter canister (it is heavy and has threads, be careful not to damage the threads) and inspect filter element for contaminants. If it is reasonably clean reinstall, otherwise install new filter. If in operation every day, this should be checked more regularly at first to determine how much compressor oil is in the gas. If initial checks show little oil then inspections can be extended. The goal is that this should need draining only every 90 days. The filter has a differential pressure indicator to view for filter restriction however this is 15

16 effective only when tank pressure is low and engines are using maximum gas flow. ECU screen values will normally flicker around some but should basically be fairly stable. Check the gas flow rate (home screen) value at fixed operating points. It should be near its normal set point depending on the notch. Presently 60 to 70 SCFM, notches 5-8, for Cummins powered Locomotives, and SCFM, for GE powered locomotives. The Gas Filter by the engine is mostly there to catch any debris from the coupling and uncoupling as well as any pipe scale. The gas itself should be very clean. The filter should be replaced annually or as necessary. The differential pressure can be measured and should not exceed 2 psi when testing in notches 5-8. Air operated Gas Shut Off Valves (GCOV and LSO) should have annual seal lubrication. Do this by venting the gas pressure, dismantle the valve, and using any quality seal lube grease like a silicone based seal glide. Replace the seals if they show any damage or every 5 years. Regulators should have new seals every 5 years or sooner if problems appear. Components that have moving parts probably will need replacement or refurbishment every 10 years. Detail Information Evaluation of Proper Operation: The engine operation with gas requires that the engine is producing power. Locomotives with the self-load feature will make inspection much easier. Locomotives without this feature will require either, riding the locomotive and inspecting it while it is producing power, or application of load bank. Proper engine operation appears the same as with strait diesel. The engine sound is likely to be somewhat quieter in the dual mode but may not be noticeable. There should be stable readings of both engine speed and power. The system information screen should be green and there should be no noticeable sound of combustion knock. SCFM: Because the engine operation will hardly be any different than strait diesel you may wonder how much gas is actually being supplied. The SCFM reading available from the information screen is a good indication that the system is operating properly. This number indicates the amount of gas flow into the engine and will be adjusted depending on power. Generally in the upper notches you will expect gas flows to be: SCFM for Cummins engines SCFM for GE engines 16

17 If the number is fairly low (0-30) then the system may be having a problem trying to supply gas to the engine. The Differential Pressure Transducer provides the primary signal used by the SFCM for calculating flow. Circuit Breaker: Inside the ECU is a 5A circuit breaker for the power to the GFCV. If this switch is Off, the system would function without much change except that very little gas would be supplied to the engine. If your SCFM value is low, this would be a first good item to inspect. V0 Trim: Inside the ECU on the computer itself there are two trim pots. V0 and V1. V1 is not used. V0 can be turned down (counter clockwise) to reduce the amount of gas delivered to the engine. Normally this is left fully clockwise for the full, programmed amount of fuel replacement. For diagnostics the trim pot can be turned down to increase the level of diesel used and evaluate the engines operation. The value for this variable can be read on the Trims screen, V0. Engine Control Unit: Servicing the ECU should only be done by qualified persons. Power to the ECU is disconnected by removing the power connector on the bottom left J1. Always remove power before disconnecting any hardware. The electronic modules are robust but electrostatic discharge precautions should be observed while handling the hardware. Power for the system comes form the locomotive batteries, through a circuit breaker to a 72 to 24 volt converter module. Inside the ECU is a power module to create a stable 24 volts for the computer and a 5 volt for system sensors. All of the devices of the conversion system operate through the 72 volt power converter module. Engine Knock: Knock (detonation) is a term used to describe undesirable combustion. When the speed of combustion gets to high, cylinder pressures becomes ragged and the peak pressure climbs to levels above what the engine is designed to withstand. Knock is affected by a number of different things; high temperatures, fuel gas content, engine health, and/or excessive gas to air or diesel ratio just to name a few. Knock sensors and controls are used to protect the engine in the event that something causes knock. The knock sensor generates a voltage signal proportional to the amplitude and frequency of vibration. The signal from the sensors goes to a dedicated control device. The signal is then filtered and measured for size. If the signal from any sensor exceeds the threshold, the computer is notified. If the computer receives excessive knock report signals, then it determines that more diesel should be delivered to avoid knock. The computer writes new fuel control values to a temporary fueling table for optimum fuel replacement without knock. 17

18 When the ECU power is removed the temporary table values are reset to original table values. It is best to keep power on the ECU and retain the modified values. If the signals continue, then the computer switches off gas mode and operates on diesel only. Switching the mode switch back to diesel will reset the latched limit and gas operation should resume. The knock system should be inspected by connecting to it with a laptop computer through a null modem cable or USB. Run the software for the system Denedit.exe. Select connect with the proper serial connector. Select the Mode Tab, check the measure box and select Ch1. You can view the knocking intensity meter and see that when you select each of the 16 channels you have a reasonable level of signal with the needle in the yellow zone. You will most likely need to increase engine speed to throttle 8, but it is not necessary to do a load test or even operate on gas. This test is just to insure that the sensors are connected and working properly. The knock system is intentionally set to ignore low signals to avoid false trouble when the engine is at idle therefore it is important to inspect the function of the sensors. The knock system is configured so that when there is no knock and the system is functioning properly, the controller is sent 5 volts. Lower voltage indicates knock or a system problem. The knock system uses a sensor to detect the position of the engine, typically via the camshaft or a target rotating at camshaft speed and timing. The sensor is set at one turn out from contact with the highest point of the target or gear. For GEA locomotives with Cummins engines you must be very careful to set the sensor gap when cam lobe is aligned with the sensor. For GE locomotives with GE engine there is only one target hole in the cam gear and the sensor can be checked anywhere except at 335 degrees. Gas piping and controls: The gas pressure regulator on the locomotive is set to: 28 inches WC on GEA locomotives with Cummins engines 16 PSI on GE locomotives with GE engines The regulator should not need adjusting. The pressure of gas without flow is normally higher than the set point and adjustments to the pressure should only be done after determining that the pressure is high while flowing. Sensors: The sensors should provide years of service without problems. A damaged sensor can be replaced easily with a new sensor with two exceptions. The barometer and engine gas pressure work together and are very sensitive. The sensor zero values must be programmed using a laptop to modify the controller code. Refer to technical bulletin from ECI for this repair procedure. 18

19 Leak Detection System: The LDS is a protection system to turn the off the gas supply in the event that a leak develops in the gas piping on the locomotive. The control module is mounted in the locomotive electrical cab. It is powered with 24 volts from the 72 to 24 volt converter. The LDS has 2 to 4 sensors connected to it. It is configured to be fail safe, if it is not powered or has detected a leak its control circuit is open. A bad sensor will only indicate a fault. After a short warm up from being turned on it will close its control circuit. It will open the circuit and sound its alarm if it detects gas concentrations greater than 2.5% gas in air. There is no need for calibration. The system has a short time delay upon sensing gas and will take a few seconds to trip when making tests. You can test the system with any hydrocarbon gas, testing should be done approximately every 90 days. If a sensor fails it can be replaced with a new sensor by turning off power and replacing the sensor. Turning on the power will auto calibrate, there is no need for calibration gas. Pressure Reducing Skid: The PRS takes the high pressure gas supply, reduces the pressure and heats the gas back to normal levels, and protects the locomotive from possible overpressure condition. Normally the skid requires no maintenance and should not be tinkered with. There are six adjustable devices on the skid. Primary Pressure Reduction: The primary regulator reduces the gas pressure from the storage tanks. The regulator is a dome loaded design whereby air pressure applied to it will turn it on. The gas pressure will equal the pressure of the air on the dome (locomotive air pressure). Air Pressure Control for Primary Pressure Reduction (PRS): Air supply to the dome of the primary regulator is controlled on the locomotive with a solenoid valve. The solenoid valve will be activated when the Leak Detection System is operational and detects no leaks, when the engine run relay is closed (typically Fuel Pump Relay) and when the train brakes are set up. On two engine locomotives these controls come from engine #2. There are quick exhaust valves on both the source and destination ends of the air system. These valves work to quickly reduce the air and close the gas supply when the air supply is shut off. On the PRS there is a restriction valve so that the air pressure on the dome of the regulator builds slowly resulting in the gas pressure also building at a comfortable rate. The restriction can be adjusted for a 1 2 second rise time. The level of air pressure might not be adjusted on the locomotive, just full air is OK or regulated to some lower level, >50 psi. 19

20 Pressure Relief: The gas leaving the high pressure regulator is routed past a high volume pressure relief valve. This safety device will quickly vent any gas above its set value. The valve is pilot operated and set for 150 PSI. It is capable of limiting the system pressure to 250 psi even if the primary regulator has completely failed and the tanks are at maximum pressure. ECI recommends checking this valves operation annually. To check this operation apply air pressure to the high pressure regulator in a manner that you can control and increase it above the relief valve setting, increasing it until the pressure relief valve operates. The pilot pressure is adjustable with its regulator but should never need adjusting. Gas Heating: After passing the relief valve the gas is routed into a heat exchanger where it can be heated back up to normal temperatures. The heat comes from the engine water. Engine water flow is controlled with a valve that has a measuring probe in the gas down stream of the heat exchanger. The valve setting is adjustable but it should be left at a fairly low setting near 70F. Gas temperature is not critical. The heat system is necessary because without it gas temperatures will go well below zero when storage tank pressure is high. When the storage pressure is low the gas temperature will not droop as much and thus the need for an automatic flow control valve. The automatic valve also has a small bypass valve so that there is always some water circulating through the heat exchanger to avoid a quick freeze. The bypass valve is a ball type and should be at ½ turn open, 45 degrees. Secondary Pressure Reduction: After the gas is heated it is routed through a second pressure regulator. This regulator will take the gas from about 125PSI (this pressure is locomotive type dependent but in all cases equal to the air pressure on the dome loaded high pressure regulator) to about 30 PSI (25-45). The setting of this regulator should be checked when there is a small amount of gas flowing. When the engine is operating on gas at full load this pressure will droop to approximately to 25-35PSI. At no flow conditions this regulator typically will leak and allow down stream pressures to be 60 PSI, or more. Secondary Pressure Relief: If the secondary pressure regulator has a problem or even just a small leak in its seat, at no flow conditions down stream pressures would increase so a second pressure relief valve is provided to protect the locomotive from excess pressure. The set pressure is 75PSI. 20

21 Trouble Shooting Problem Symptom Cause / Cure Not running on gas Switch is on but screen light remains Orange Controller finds a fault or limit with one or more signals. Go to limit and or lim2 screen to Engine speed No gas flow reading Knock signal forces diesel operation Engine is running but ECU reading shows zero Engine is running with load and the screen is green but there is no reading for gas flow ECU screen indicates that KNO signal is cause for diesel only operation learn the problem. Sensor adjustment, bad connection, bad sensor, bad driver module or faulty PLC. See notes below for explanation of details. No gas is being given to the engine. Check GFCV circuit breaker in the ECU, check wiring of the GFCV. Contact ECI for further support. There are several possibilities, bad engine position sensor signal faulty wiring connections or actual knock may occur. See below for more details. Engine Speed Signal: When the engine is running the PLC indicator for X0 should be green (not very bright), meaning that 24V is being pulsed on the #1 terminal. If there is voltage here and the green light is out, consider that common and 24V are applied to the terminals 9 and 10 respectively on the PLC connection module, check connections. Closely check the ribbon cable connecting the termination module to the PLC. If these are good then the PLC is faulty. If the voltage is not on terminal 1 (engine running voltage should be 5-15 VDC with normal volt meter or with a scope should be 24 volt pulses) then it is possible that there is a break in the circuit or an open sensor. Check for voltage on the driver module position D volts on this terminal is normal and when running this signal will have small dips in the voltage for each gear tooth passing the sensor. Disconnect the wire D20 on driver module and check the wire for 24V to common, this indicates you have power through the sensor, connected you get a back feed from the board. If this is not the case check the sensor and or find the wire break. If this voltage is good, change the module. Knock System: The knock system uses a sensor to determine engine position. This sensor causes the indicator light to blink when the engine is running. If the ISU indicator is not blinking when the engine is running you system will indicate that there is a knock limit. First check the 21

22 wiring and connections. Next check the sensor gap. It should be out one turn from contact. See Detailed Information section for more information. If for reason there are any difficulties or limitations after reading the supplied literature. Please contact ECI for any additional technical support questions you may have at (253) Tacoma WA., U.S.A. 22