Most of the parameters are common to engines that use oxygen feedback and to engines that use charge density. However, some of the parameters are associated only with oxygen feedback or with charge density.
| Configuration Parameters for G3500B Engines | |||||
|---|---|---|---|---|---|
| Parameter | Oxygen Feedback | Charge Density | |||
| Timing Control | |||||
| "First Desired Timing" | Yes | Yes | |||
| "Second Desired Timing" | Yes | Yes | |||
| Air/Fuel Ratio Control | |||||
| "Fuel Quality" | Yes | Yes | |||
| "Gas Specific Gravity" | Yes | Yes | |||
| "Desired Oxygen at Full Load" | Yes | No | |||
| "Oxygen Feedback Enable Status" | Yes | No | |||
| "Fuel Specific Heat Ratio" | No | Yes | |||
| "Desired Emission Gain Adjustment" | No | Yes | |||
| "Air/Fuel Proportional Gain" | Yes | Yes | |||
| "Air/Fuel Integral Gain" | Yes | Yes | |||
| Speed Control | |||||
| "Low Idle Speed" | Yes | Yes | |||
| "Minimum High Idle Speed" | Yes | Yes | |||
| "Maximum High Idle Speed" | Yes | Yes | |||
| "Engine Accel. Rate" | Yes | Yes | |||
| "Desired Speed Input Configuration" | Yes | Yes | |||
| "Governor Type Setting" | Yes | Yes | |||
| "Engine Speed Droop" | Yes | Yes | |||
| "Governor Proportional Gain" | Yes | Yes | |||
| "Governor Integral Gain" | Yes | Yes | |||
| "Governor Derivative Gain" | Yes | Yes | |||
| "Auxiliary Proportional Governor Gain 1"(1) | Yes | Yes | |||
| "Auxiliary Integral Governor Gain 1"(1) | Yes | Yes | |||
| "Auxiliary Derivative Governor Gain 1"(1) | Yes | Yes | |||
| Start/Stop Control | |||||
| "Driven Equipment Delay Time" | Yes | Yes | |||
| "Crank Terminate Speed" | Yes | Yes | |||
| "Engine Purge Cycle Time" | Yes | Yes | |||
| "Engine Cooldown Duration" | Yes | Yes | |||
| "Cycle Crank Time" | Yes | Yes | |||
| "Engine Overcrank Time" | Yes | Yes | |||
| "Engine Speed Drop Time" | Yes | Yes | |||
| "Engine Pre-lube Time Out Period" | N/A | ||||
| Monitoring and Protection | |||||
| "High Inlet Air Temp Load Set Point" | Yes | Yes | |||
| Power Monitoring | |||||
| "Generator Output Power Sensor Scale Factor"(1) | Yes | Yes | |||
| "Generator Output Power Sensor Offset"(1) | Yes | Yes | |||
| "Engine Output Power Configuration" | No | Yes | |||
| "Engine Driven Accessory Load Configuration" | No | Yes | |||
| Information for the ECM | |||||
| "Engine Serial Number" | Yes | Yes | |||
| "Equipment ID" | Yes | Yes | |||
| "Customer Password #1" | Yes | Yes | |||
| "Customer Password #2" | Yes | Yes | |||
| "Total Tattletale" | Yes | Yes | |||
| (1) | This parameter is not used for industrial arrangements. |
The "Desired Timing" parameters allow the customer to program the timing of the ignition spark for the engine. The desired timing value can be changed while the engine is running or while the engine is stopped. The value that is entered for the desired timing is the ignition timing when the engine is operating at rated speed and at full load.
Note: The actual ignition timing at a given instance may vary from the desired timing value. This variance is due to variations in the engine speed or the detonation.
The range for programming the desired timing is 0 to 40 degrees before the top center (TC) position.
The "First Desired Timing" is determined with the methane number of the primary fuel that is used. Use the Engine Performance Sheet, "Fuel Usage Guide". The ECM selects the "First Desired Timing" when terminal J1-20 is not connected to ground.
The "Second Desired Timing" is determined with the methane number of the alternate fuel that is used and the Engine Performance Sheet, "Fuel Usage Guide". The ECM selects the "Second Desired Timing" when terminal J1-20 is connected to ground. If an alternate fuel is not used, enter the same timing that was entered in the "First Desired Timing".
Before the initial start-up, a current gas analysis is required. Periodic gas analyses are also recommended. Data from the gas analysis must be entered into Caterpillar Software, LERW4485, "Gas Engine Rating Pro (GERP)". The results are programmed into the ECM.
Note: Use the Caterpillar Software, LERW4485, "Gas Engine Rating Pro (GERP)" to calculate the values for the following parameters. Use of only the data from the gas analysis can result in incorrect settings.
This parameter defines the Low Heat Value (LHV) of the fuel. The air/fuel ratio control of the ECM will compensate for some inaccuracy in this setting. The ECM assumes a corrected value that is multiplied by the "Fuel Correction Factor". This factor can be displayed on the Cat ET screen.
The "Fuel Quality" parameter can be used to change the air/fuel ratio when the engine is operating in the open loop mode. To richen the air/fuel mixture, reduce the value. The calculation will compensate for the reduced LHV by increasing the fuel flow. To lean the air/fuel mixture, increase the value. The calculation will compensate for the increased LHV by reducing the fuel flow.
This parameter defines the specific gravity in relation to the specific gravity of air for the fuel. The ECM does not use this information. The ECM provides the information to the fuel metering valve via the CAN data link. Some fuel metering valves require an input for the "Gas Specific Gravity" in order to precisely meter the fuel flow.
The ECM contains an oxygen map that is programmed at the factory. The "Desired Oxygen At Full Load" parameter is used to trim the oxygen map when the engine is in "Oxygen Feedback" mode. Measure the exhaust oxygen or the NOX emissions at the tail pipe. Increase the "Desired Oxygen At Full Load" parameter order to lean the engine. Decrease the "Desired Oxygen At Full Load" parameter in order to richen the fuel mixture.
"Oxygen Feedback Enable Status"
The "Oxygen Feedback Enable Status" can be set to "Enable" or to "Disable". The engine will not operate in the "Oxygen Feedback" mode when the "Oxygen Feedback Enable Status" parameter is disabled. This feature allows the feedback mode to be disabled in order to troubleshoot. For example, the disabling of this feature can help determine whether the air/fuel ratio control is the cause of instability.
If the signal from the oxygen sensor is not available, the ECM will not have the feedback necessary for maintaining consistent exhaust emissions.
If there is a problem with the oxygen sensor, this parameter can be set to "Disable". This setting will allow the engine to run in the open loop mode until a new sensor is obtained. During operation in this mode, an emissions analyzer must be used to verify the emissions level. The "Fuel Quality" parameter is adjusted in order to adjust the air/fuel mixture.
When the "Oxygen Feedback Enable Status" is enabled, adjustment of the "Fuel Quality" parameter does not affect the air/fuel ratio. Do not adjust the "Fuel Quality" parameter when the "Oxygen Feedback Enable Status" is enabled.
Note: Do not operate an engine that is unattended in the open loop mode if the fuel has an LHV that is changing. The engine risks a shutdown due to lean misfire or to detonation.
This parameter is a ratio of the specific heat at a constant pressure and at a constant volume for the fuel . The ratio is also known as "k". The ratio is related to the expansion of the gas across the fuel metering valve. The ECM does not use this information. The ECM provides the information to the fuel metering valve via the CAN data link. Some fuel metering valves require an input for the "Fuel Specific Heat Ratio" in order to precisely meter the fuel flow.
For this engine, the fuel-specific heat ratio parameter has a minimal effect on the fuel calculation during operation. If the fuel-specific heat ratio is unknown for the current fuel, enter the nominal value of 1.4 for this parameter.
"Desired Emission Gain Adjustment"
Only engines that use charge density use this parameter.
This parameter is an adjustment for the level of the exhaust emissions for engine operation at full load. The adjustable range is 85 to 115.
Refer to Testing and Adjusting, "Air/Fuel Ratio Control - Adjust".
The "Air/Fuel Proportional Gain" determines the speed of the response for the fuel metering valve during an adjustment between desired and actual valve position.
The factory default setting is 0. The adjustable range is −50 to +50. Negative values reduce the response speed of the fuel metering valve. Positive values increase the response speed of the fuel metering valve.
The "Air/Fuel Integral Gain" determines the response of the fuel metering valve to the error that is accumulated over time for the air/fuel ratio.
The factory default setting is 0. The adjustable range is −50 to +50. Negative values reduce the response speed of the fuel metering valve. Positive values increase the response speed of the fuel metering valve.
Program this parameter to the desired low idle rpm. The low idle rpm can be programmed within the range of 500 to 1100 rpm.
Program this parameter to the desired minimum high idle rpm. The actual high idle speed is regulated by the desired speed input. The regulation is linear in proportion to the input. An input of 0 percent results in the minimum high idle rpm and an input of 100 percent results in the maximum high idle rpm.
For the 50 Hz arrangement, the minimum high idle speed can be programmed between 900 rpm and 1500 rpm. The default value is 1400 rpm.
For the 60 Hz arrangement, the minimum high idle speed can be programmed between 900 rpm and 1800 rpm. The default value is 1600 rpm.
For an industrial arrangement, the minimum high idle speed can be programmed between 650 rpm and 1350 rpm. The default value is 1350 rpm.
The "Minimum High Idle Speed" and the "Maximum High Idle Speed" determine the slope of the desired speed input.
Program this parameter to the desired maximum high idle rpm. The actual high idle speed is regulated by the desired speed input. The regulation is linear in proportion to the input. An input of 0 percent results in the minimum high idle rpm and an input of 100 percent results in the maximum high idle rpm.
For the 50 Hz arrangement, the maximum high idle speed can be programmed between 1500 rpm and 1900 rpm. The default value is 1600 rpm.
For the 60 Hz arrangement, the maximum high idle speed can be programmed between 1800 rpm and 2200 rpm. The default value is 2000 rpm.
For an industrial arrangement, the maximum high idle speed can be programmed between 1200 rpm and 1900 rpm. The default value is 1350 rpm.
This parameter controls the rate for engine response to a change in the desired engine speed. For example, the engine can be programmed to accelerate at a rate of 50 rpm per second when the "Idle/Rated" switch is turned to the "Rated" position.
This parameter is also used for the rate of deceleration for the engine.
"Desired Speed Input Configuration"
This parameter determines the signal input to the ECM for control of the desired speed. The signal can be either 0 to 5 VDC or 4 to 20 mA.
Note: The ECM is not configured to accept a pulse width modulated signal for input of the desired engine speed. If you try to select a Pulse Width Modulated input (PWM), the ECM will reject the selection. An error will be generated.
The "Governor Type Setting" parameter can be set to "Droop Operation" or to "Isochronous Mode". This setting is dependent upon the application of the engine.
This programmable parameter allows precise control of the speed droop. The "Governor Type Setting" parameter must be set to "Droop". The droop can be programmed to a value between 0 and 10 percent.
Refer to Testing and Adjusting, "Engine Governing - Adjust" for the adjustment procedure for the governor.
This parameter is based on a proportional multiplier. The "Governor Proportional Gain" determines the response speed of the throttle actuator when adjusting engine speed. Increasing this value provides a faster response to the difference between the actual speed and the desired speed.
This parameter changes the reaction of the throttle actuator when the "Grid Status" parameter is "Off". If changing this value causes no effect, check the "Grid Status" in order to make sure that the status is "Off".
This parameter is based on an integral multiplier. The "Governor Integral Gain" controls the speed for elimination of the error in the difference between the actual speed and the desired speed. Increasing this value provides less damping.
This parameter changes the reaction of the throttle actuator when the "Grid Status" parameter is "Off". If changing this value causes no effect, check the "Grid Status" in order to make sure that the status is "Off".
This parameter is based on a derivative multiplier. The "Governor Derivative Gain" is used to adjust for the time delay between the control signal and the movement of the throttle actuator. If this value is too low, the engine speed will slowly hunt. If this value is too high, the engine speed will rapidly fluctuate.
This parameter changes the reaction of the throttle actuator when the "Grid Status" parameter is "Off". If changing this value causes no effect, check the "Grid Status" in order to make sure that the status is "Off".
"Auxiliary Proportional Governor Gain 1"
This parameter is not used for industrial arrangements.
This parameter is based on a proportional multiplier. The "Auxiliary Proportional Governor Gain 1" determines the speed of the response of the fuel actuator when adjusting the engine speed. Increasing this value provides a faster response to the difference between the actual speed and the desired speed.
This parameter changes the reaction of the throttle actuator when the "Grid Status" parameter is "On". If this value is changed and the "Grid Status" is "Off", the stability of the engine will not change. If changing this value causes no effect, check the "Grid Status" in order to make sure that the status is "On".
"Auxiliary Integral Governor Gain 1"
This parameter is not used for industrial arrangements.
This parameter is based on an integral multiplier. The "Auxiliary Integral Governor Gain 1" controls the speed for elimination of the error in the difference between the actual speed and the desired speed. Increasing this value provides less damping.
This parameter changes the reaction of the throttle actuator when the "Grid Status" parameter is "On". If this value is changed and the "Grid Status" is "Off", the stability of the engine will not change. If changing this value causes no effect, check the "Grid Status" in order to make sure that the status is "On".
"Auxiliary Derivative Governor Gain 1"
This parameter is not used for industrial arrangements.
This parameter is based on a derivative multiplier. The "Auxiliary Derivative Governor Gain 1" is used to adjust for the time delay between the control signal and the movement of the throttle actuator. If this value is too low, the engine speed will slowly hunt. If this value is too high, the engine speed will rapidly fluctuate.
This parameter changes the reaction of the throttle actuator when the "Grid Status" parameter is "On". If this value is changed and the "Grid Status" is "Off", the stability of the engine will not change. If changing this value causes no effect, check the "Grid Status" in order to make sure that the status is "On".
The ECM accepts an input from the driven equipment that indicates when the equipment is ready for operation. When the input is grounded, the driven equipment is ready. The ECM will not start the engine until this input is grounded.
The ECM can be programmed to wait for a predetermined delay time after receiving a start command before a start attempt. This delay allows the driven equipment to get ready for operation.
When the ECM receives a start command, the ECM will wait for the amount of time that is programmed into the "Driven Equipment Delay Time". If the "Driven Equipment Delay Time" elapses and the input is not grounded, an event code is activated. The engine will not start.
If the "Driven Equipment Delay Time" is programmed to "0", the delay is disabled. If the ECM receives a start command and the driven equipment is not ready, an event code is activated. The engine will not start.
The ECM disengages the starting motor when the engine speed exceeds the programmed "Crank Terminate Speed". The default value of 250 rpm should be sufficient for all applications.
The "Engine Purge Cycle Time" is the duration of time for the engine to crank without fuel before the crank cycle. The "Engine Purge Cycle Time" allows any unburned fuel to exit through the exhaust before the fuel and the ignition are enabled.
When the ECM receives a "Stop" request, the engine will continue to run in the "Cooldown Mode" for the programmed cooldown period. The "Cooldown Mode" is exited early if a request for an emergency stop is received by the ECM. If the "Engine Cooldown Duration" is programmed to zero, the engine will immediately shut down when the ECM receives a "Stop" request.
The "Cycle Crank Time" is the amount of time for activation of the starting motor and of the gas shutoff valve for start-up. If the engine does not start within the specified time, the attempt to start is suspended for a "Rest Cycle". This delay is equal to the "Cycle Crank Time".
The "Engine Overcrank Time" determines the length of time for the ECM to attempt to start the engine. An event is generated if the engine does not start within this time period
| Examples of the Settings for Start-up | |
| Parameter | Time |
| "Purge Cycle Time" | 10 seconds |
| "Cycle Crank Time" | 30 seconds |
| "Overcrank Time" | 280 seconds |
The following sequence will occur if the parameters are programmed according to the example in Table 2:
- The fuel and the ignition are OFF. The engine will crank for 10 seconds in order to purge gas from the engine via the exhaust system.
- The fuel and the ignition are enabled. The engine will continue to crank for a maximum of 30 seconds.
- If the engine does not start, the ignition, the fuel, and the starting motor are disabled for a 30 second "Rest Cycle".
With this example, a complete cycle is 70 seconds: a purge cycle of 10 seconds, a cycle crank of 30 seconds and a rest cycle of 30 seconds. The "Overcrank Time" of 280 seconds allows a maximum of four crank cycles.
This parameter is activated when the ECM receives the signal for stopping the engine. This input ensures the shutdown in case the Gas Shutoff Valve (GSOV) does not close.
After the cool down period has elapsed, the ECM signals for the GSOV to close. The ignition continues until the engine speed drops below 40 rpm. If the engine rpm does not drop below 100 rpm within the programmed speed drop time, the ECM terminates the ignition and the ECM issues an emergency stop. The speed drop time can be configured in the configuration screen using Cat ET.
"Engine Pre-Lube Time Out Period"
At the time of this publication, this parameter is not active.
"High Inlet Air Temp Engine Load Setpoint"
The programmable setpoint is a value that separates low engine load from high engine load for events that are activated by high inlet air temperature. An "Engine Load Factor" can be displayed on a Cat ET status screen. When the load factor setpoint is reached and the inlet air temperature increases to the trip point, the following event is activated:
- "High Inlet Air Temperature at Low Engine Load"
When the load factor setpoint is exceeded and the inlet air temperature increases to the trip point, the following event is activated:
- "High Inlet Air Temperature at High Engine Load"
The ECM monitors the generator output power in order to control the air/fuel ratio. The ECM uses an output from one of the following sources in order to monitor the generator output power:
- Electronic Modular Control Panel II+ (EMCP II+)
- Programmable Logic Controller (PLC)
- Wattmeter
The PLC and the wattmeter are also called power sensors.
The ECM uses the values of the "Power Monitoring" parameters to estimate the generator actual power output. The ECM estimate of the generator actual power output is displayed on Cat ET as the "Generator Real kW". If the value of this parameter is within one percent of the generator actual power output, the ECM will accurately control the air/fuel ratio.
"Generator Output Power Sensor Scale Factor"
This parameter is not used for industrial arrangements.
If the generator is equipped with the EMCP II+, information on the generator output is provided to the ECM via the Cat data link. The value for the "Generator Output Power Sensor Scale Factor" parameter is correctly programmed at the factory. No further adjustment is necessary for this parameter.
If the generator is equipped with a power sensor, the sensor signal increases from 0 to 4.8 VDC as the output increases to the maximum. The maximum output is 110 percent of the generator rated output. For example, if the generator has a rated output of 1700 ekW, the maximum output is 1870 ekW. When the generator output is 1870 ekW, the power sensor will provide a signal of approximately 4.8 VDC.
The ECM requires a scale factor in order to estimate the generator output. The equation that is used to determine the scale factor is provided in Table 3.
| Computing the Value for the "Generator Output Power Sensor Scale Factor" |
| (R x 1.1) ÷ 4.8 |
| R is the generatorrated output in kilowatts. |
For example, if the generator rated output is 1700 ekW, the correct value for the "Generator Output Power Sensor Scale Factor" parameter is 390. In this example, the relationship between the voltage level of the signal and the generator output is shown in Illustration 1 .
| |
| Illustration 1 | g01062926 |
|
In this example, the value of the "Generator Output Power Sensor Scale Factor" parameter is 390. | |
The ECM multiplies the signal voltage by the scale factor in order to estimate the generator output. In this example, a signal level of 3.5 VDC indicates that the generator output is approximately 1365 ekW.
After the ECM estimates the generator output, the ECM adds the value of the "Generator Output Power Sensor Offset" parameter to the estimate. The final value refines the ECM estimate of the generator actual output.
"Generator Output Power Sensor Offset"
This parameter is not used for industrial arrangements.
If the generator is equipped with the EMCP II+, information on the generator output is provided to the ECM via the CAT data link. The value for the "Generator Output Power Sensor Offset" parameter is correctly programmed at the factory. No further adjustment is necessary for this parameter.
If the generator is equipped with a power sensor, the sensor output may not be zero when the generator output is zero. When this condition is present, adjust the offset voltage for the sensor. The offset voltage may be positive or negative. In most cases, the offset voltage is low. Therefore, the value of the "Generator Output Power Sensor Offset" parameter must be set to zero.
The offset voltage must be measured before you change this parameter from zero. To measure the offset voltage, refer to Troubleshooting, "Generator Output Power Readings Do Not Match". If the offset voltage is less than 0.01 VDC, the value of the "Generator Output Power Sensor Offset" must be set to zero.
The value of this parameter is in units of ekW. The minimum programmable value for this parameter is −327 ekW. The maximum programmable value for this parameter is 200 ekW.
The ECM adds the value of the "Generator Output Power Sensor Offset" parameter to the value that is determined by the "Generator Output Power Sensor Scale Factor" parameter. This value refines the ECM estimate of the generator actual output.
The final estimate of the generator actual output is displayed on Cat ET as the "Generator Real kW" parameter. If the value of this parameter is within one percent of the generator actual power output, the ECM will accurately control the air/fuel ratio.
"Engine Output Power Configuration"
This parameter applies to all sources.
The value of the "Engine Output Power Configuration" parameter is the full load rating of the engine in ekW. The rating is stamped on the Information Plate. During operation, the ECM uses this value to determine the engine load as a percentage of the maximum load.
"Engine Driven Accessory Load Configuration"
This parameter applies to all sources.
The value of this parameter is the rated load of the auxiliary equipment such as a radiator fan that is directly driven by the engine. The value is in units of ekW. The ECM adds this load to the estimate of the generator actual output in order to determine the total load on the engine.
This parameter enables the oxygen sensor and the oxygen buffer to be energized when the engine is not running. The override facilitates troubleshooting the electrical circuit of the sensor. This parameter also allows verification of the calibration of the oxygen sensor.
The engine serial number is programmed into the ECM at the factory. The number is stamped on the engine Information Plate.
The customer can assign an "Equipment ID" to identify the equipment.
Two customer passwords can be entered. The passwords are used to protect certain configuration parameters from unauthorized changes.
Note: Factory level security passwords are required for clearing certain logged events and for changing certain programmable parameters. Because of the passwords, only authorized personnel can change some of the programmable items in the ECM. When the correct passwords are entered, the changes are programmed into the ECM.
This item displays the number of changes that have been made to the configuration parameters.