20775904 Volvo.Penta Fitting

Recommendations for Programming Some of the Parameters
Gain for the Governor
For the governor gain, select a value of zero for the adjustments on initial start-up. These values should enable speed control, but the values may not provide optimum performance.After you adjust the governor, always test the governor stability by interrupting the engine speed. To interrupt the engine speed, use Cat ET. Test the ability of the governor to adjust to changes in the load. Operate the engine through the entire range of speeds and loads to ensure stability.Illustration 1 shows some typical curves for transient responses.
Illustration 1 g00806254
(Y) Engine speed
(X) Time
(1) The gain is too high and the stability is too low. There is a large overshoot on start-up and there are secondary overshoots on transient loads.
(2) The gain is slightly high and the stability is slightly low. There is a slight overshoot on start-up but the response to transient loads is optimum.
(3) The gain is slightly low and the stability is slightly high. There is optimum performance on start-up but slow response for transient loads.
(4) The gain is too low and the stability is too high. The response for transient loads is too slow.
(5) The response to transient loads is adjusted for optimum performance."AUX1 GOV GAIN" - To enable the proportional gain, stability, and compensation of the auxiliary governor, terminal 328 must be grounded to the − Battery side. A switch may be installed between terminal 328 and the − Battery side. When the switch closes terminal 328 to the − Battery side, the auxiliary governor gain is enabled. The status can be viewed on Cat ET. When the circuit is opened, the auxiliary governor is disabled and the primary governor is enabled."GOV P-GAIN" and "AUX1 GOV P-GAIN" - Slowly increase the proportional gain until the engine becomes slightly unstable. Slowly reduce the gain until performance is stable. If the gain is too low, the engine may have excessive overshoot. Overshoot can cause an engine shutdown during changes in load."GOV STAB" and "AUX1 GOV STAB" - If the engine is slowly hunting, increase the stability. If the adjustment does not stabilize the engine, slowly reduce the gain or increase the compensation."GOV COMP" and "AUX1 GOV COMP" - Raise the compensation until the throttle actuator becomes unstable or until the actuator reaches the maximum acceptable level of activity. After you raise the compensation, possibly raise the proportional gain. Use the compensation to achieve the most stable engine speed.Illustration 2 is a graphic representation of adjusting the compensation.
Illustration 2 g00806274
The increased width of the line for the actuator voltage indicates that the linkage is more active as the compensation increases.
(Y) Actuator voltage
(X) Time in seconds"LOW IDLE SPEED"
The programmed idle speed must always be less than the programmed rated speed. If the programmed idle speed is greater than the programmed rated speed, the engine will run at the idle speed. The engine will run at the idle speed regardless of the idle/rated switch position. To avoid possible problems, program the idle speed at least 300 rpm less than the rated speed."RATED SPEED"
For generator sets, the maximum allowable desired speed is equal to the rated speed plus 12 percent. If droop is used, increase the programmable rated speed to achieve the rated speed at full load.For example, if the droop is programmed to 5 percent, add 5 percent to the value for the rated speed. If the droop is 5 percent and the desired speed is 1000 rpm at full load, program the rated speed to 1050 rpm."SPEED DROOP"
To program the percent of speed droop, set the "Governor" parameter for droop operation. The droop can be programmed to a value between 0 and 10 percent.Gain for the Air/Fuel Ratio Control
For the air/fuel ratio gain, the default values are zero. Use these values for initial start-up. These values do not need adjustment unless the exhaust oxygen is unstable or the actuator does not respond quickly.Adjust the proportional gain and the stability at the same time.After adjustment, change the desired oxygen content by at least 1 percent to observe the stability of the air/fuel ratio control. Make sure that the actuator and the fuel valve are in the mid-position during normal operation. If the fuel valve is at the minimum or maximum position, the air/fuel ratio control may not be able to adjust the air/fuel mixture."A/F RATIO P-GAIN" - If the desired exhaust oxygen is rapidly fluctuating, reduce the proportional gain to stabilize the engine. If the gain is too high, the fuel valve may have excessive overshoot. Overshoot can also cause the engine speed to fluctuate."A/F RATIO STAB" - An increase of the stability reduces the time that is required to achieve the desired exhaust oxygen. If the stability is too high, large variations of exhaust oxygen and engine speed instability can occur. If the stability is too low, the actuator for the fuel valve will respond slowly to changes in the exhaust oxygen.Calibration of the Oxygen Sensor
This feature enables you to initiate calibration of the oxygen sensor. Calibration is required periodically as part of normal maintenance. Calibration can only be initiated with the engine stopped. Approximately 12 minutes are required for the calibration.When the oxygen sensor is removed from the exhaust stack and the calibration is performed, the correct oxygen level is approximately 21 percent.For instructions on calibrating the oxygen sensor, refer to Electronic Troubleshooting, SENR6413, "G3500 Engines".Removing Power from the Oxygen Buffer
This feature is used primarily for troubleshooting. This feature enables manual control of power to the oxygen buffer. The feature is used for testing the relay for the oxygen buffer and calibrating the oxygen sensor. The relay is normally energized when engine speed is detected. When engine speed is not detected, the relay is de-energized after a delay.The ECM will not allow this relay to be turned off during engine operation.To remove power from the oxygen buffer, use Cat ET.Disabling the Air/Fuel Ratio Control
Note: Disabling the air/fuel ratio does not disable the engine speed governor.When the air/fuel ratio control is disabled, the