Frequency Adjustment; Engine Speed Governor Settings; Hunting/Surging - Kohler 38RCL Manual

6.6 Frequency Adjustment

The engine speed determines the generator output
frequency; 60 Hz units operate at 1800 RPM and 50 Hz
units run at 1500 RPM. The engine speed is maintained
by the engine ECM, which controls the speed to a target
speed set by the RDC2 controller.
The operating frequency of the generator is set by
changing the Genset System Frequency using the front
panel or Kohlerr SiteTecht Software. See Figure 6-11
for engine speed and frequency parameters in SiteTech.
6.6.1

Engine Speed Governor Settings

The default setting for the engine speed adjustment is
50. This gives engine speeds of 1800 RPM for 60 Hz
models, and 1500 RPM for 50 Hz models. The setting
can be adjusted from 0 to 99. Changing the setting will
change the engine speed according to the following
formula:
(System Frequency x 30) + (Setting -- 50) = RPM
Examples:
System frequency of 60 Hz, changing the setting to 40:
(60 x 30) + (40 -- 50) = 1790 RPM
System frequency of 50 Hz, changing the setting to 60:
(50 x 30) + (60 -- 50) = 1510 RPM
The engine speed gain adjustment has no effect. The
engine speed is controlled by the engine ECM.
TP-6811 7/16
6.6.2

Hunting/Surging

The engine speed regulation gains reside in the engine
ECU and are not adjustable. Most Hunting or surging
problems are caused by fuel supply pressures that are
out of spec, dirty air filters, air intake restriction, etc. If
Hunting or surging occurs, verify the following:
The load is stable (not changing significantly).
D
The fuel pressure is within the acceptable range both
D
at no-load and full load.
The air cleaner is clean and dry.
D
There is not a buildup of leaves, etc. blocking the
D
airflow in or out of the engine compartment.
If the hunting/surging persists, refer to the engine
service manual for
procedures. See the List of Related Materials in the
Introduction of this manual for the engine service
manual part numbers.
Section 6 Component Testing and Adjustment
additional troubleshooting
83