Starting Position of the Fuel Valve
The starting position for the fuel valve is the default position when automatic control is activated. The preferred position is near the middle range of the fuel valve's travel. The default is 350 steps for the G3412 and G3516 engines. The default is 500 steps for the G3408 engine. This enables the control to maximize the amount of adjusting of the lean and rich mixtures of the air and fuel.
For the reset process, the fuel valve's motor is retracted. The control retracts the motor by attempting to open the fuel valve beyond the motor's mechanical stop. In the fully retracted position, the fuel valve is fully open. The fully retracted position corresponds to zero steps. The control keeps track of the fuel valve's position.
After zero steps are achieved, the control commands the motor to move the fuel valve for the number of steps that are programmed for the starting position. The default is 350 steps for the G3412 and G3516 engines. The default is 500 steps for the G3408 engine. The control keeps track of the number of steps that are moved. This enables the control to calculate the position of the fuel valve during operation. When the air/fuel mixture is richened, the control subtracts the corresponding number of steps. When the air/fuel mixture is leaned, the control adds the corresponding number of steps.
Resetting the motor's position prior to engine start-up is recommended. This ensures that the starting position for automatic control is obtained and the control can determine the actual position of the fuel valve during operation.
When the control is powered down, the last position of the fuel valve is recorded in non-volatile memory. Unless the fuel valve is reset to the starting position, the valve will retain the last operating position. When the motor for the fuel valve is not reset between starts of power cycles, the control may not properly display the actual position of the valve. The closed loop control system of the engine would not be affected.
The reset function is prevented if the engine is operating with a load. This is done in order to avoid resetting the motor for the fuel valve when there is a risk of disturbing the operation of a loaded engine.
| "F1" key |
| "STRT POS" key |
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| Illustration 1 | g01388953 |
To reset the fuel valve to the starting position, press the "F1" key and then press the "STRT POS" key. During this process, the screen will display "MOVING STEPPER TO START POS".
If an operator is not available for performing the resetting, the system is still compatible with a remote start-up. If the actual position of the fuel valve is not known, the control will work in order to maintain the desired NOX level.
Entering and Exiting Setup Modes 1 and 2
Entering Setup Mode 1
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| Illustration 2 | g01388948 |
Function keys | |
In order to adjust parameters in setup group 1, you must enter "Setup Mode 1". To enter "Setup Mode 1", press the function keys in this sequence: "F1", "F3", "F2" and "F4".
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| Illustration 3 | g01388946 |
Entering Setup Mode 2
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| Illustration 4 | g01388937 |
Function keys | |
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| Illustration 5 | g01388941 |
In order to adjust the parameters in setup group 2, you must already be in "Setup Mode 1". To enter "Setup Mode 2" from "Setup Mode 1", press the function keys in this sequence: "F1", "F2", "F3" and "F4".
Note: When this operation is performed, a warning will inform the operator that all of the stored values are reset to the default value.
Selecting 8 or 12 Cylinder Configuration
In order to restore all of the adjustable parameters to the default value, press the function keys in the sequence that follows: "F2" and "F3". The control must be in "Setup Mode 2".
The default configuration will be for the G3412 settings. The display screen will ask to select the factory default that is desired.
In "Setup Mode 2", pressing the sequence "F2" and "F3" will allow the choice between the factory defaults "F1" or no change "F4".
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| Illustration 6 | g01441583 |
After pressing "F1", a new screen will be displayed. Pressing "F4" will stop the process. The current settings will remain unaffected. The default values will not be restored. Pressing "F2" will restore the default values for a G3408 engine. Pressing "F3" will restore the default values for a G3412 engine. No default values are available for a G3516 engine. A G3516 engine requires tuning when starting from the G3412 engine defaults.
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| Illustration 7 | g01441592 |
After the selection has been made for G3408 or for G3412, a message will be displayed.
If "F2" has been selected, a message will appear on the display screen. Refer to Illustration 8.
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| Illustration 8 | g01441600 |
If "F3" has been selected, a message will appear on the display screen. Refer to Illustration 9.
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| Illustration 9 | g01441604 |
Note: Optimum engine transient response will not be achieved if the improper configuration has been selected.
Exiting Setup Mode 1 or Setup Mode 2
| "F4" key - In order to exit either "Setup Mode 1" or "Setup Mode 2", press "F4" twice. |
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| Illustration 10 | g01388944 |