Rheem RESIDENTIAL GENERATOR SYSTEM GEN12S - Manual (Page 19)

17
Engine Adjustment
There are regional variances in the composition of natural
gas. Each generator system is adjusted at the factory for NG
operation. If the generator output voltage or frequency
measured during Initial Start-Up (paragraph #9, earlier) is
outside the listed ranges, the combustibility of the gas
supplied at the installation site may be substantially different.
To adjust the engine for this difference, proceed as follows.
1. Open the oil drain and control panel access doors.
2. Remove the four screws that hold the circuit breaker
cover to the air intake guard (Figure 14).
3. Connect an accurate frequency meter to the line side of
the generator’s main circuit breaker.
4. Ensure that the 15 Amp fuse is installed.
5. Set the generator’s main circuit breaker ON.
6. Set the generator’s system switch to AUTO.
7. Push MANUAL OVER-RIDE switch on control panel.
When the engine starts, allow it to warm up for five
minutes.
8A. For a 12kW generator, normal no load frequency is
62.0 to 62.5 Hz. If adjustment is needed at no load,
slowly rotate the governor adjustment nut (Figure 15)
clockwise and/or counterclockwise until frequency is
62.0 to 62.5 Hz.
8B. For a 15kW generator, normal no load frequency is
62.0 to 62.5 Hz. If adjustment is needed at no load,
slowly rotate the governor adjustment screw
(Figure 16) clockwise and/or counterclockwise until
frequency is 62.0 to 62.5 Hz.
9. Push and hold MANUAL OVER-RIDE switch on control
panel again until engine stops.
10. Turn the service disconnect to the transfer switch off.
After a short time delay, the transfer switch will connect
to the generator.
11. Load generator to full load.
12. Connect an accurate frequency meter to the load side of
the generator’s main circuit breaker. Frequency should
be above 57.0 Hz.
13. If frequency is below 57.0 Hz, slowly rotate the
governor adjustment nut or screw clockwise and/or
counterclockwise until frequency is above 57.0 Hz.
14. Turn the service disconnect to the transfer switch on.
The transfer switch will connect to the utility after five
minutes.
15. After the engine has stopped running,
• If an adjustment was made in step 13, repeat steps
3 through 9.
• If an adjustment was not made in step 13, proceed to
step 16.
IMPORTANT: If the no load frequency falls out of the no load
parameter after full load adjustment is made, contact an
authorized service center.
16. Reinstall the circuit breaker cover to the air intake
guard.
17. Close the oil drain and control panel access doors.
This completes the generator installation process. Proceed
with transfer switch and other system component
installation. Be sure to perform the Installation Inspection.
Figure 14 — Accessing Back of Circuit Breaker
Figure 15 — Governor Adjustment Nut
Governor
Adjustment
Nut
Figure 16 — Governor Adjustment Screw
Governor
Adjustment
Screw