ARMY TM 9-6115-644-24
AIR FORCE TO 35C2-3-446-12
MARINE CORPS TM 09249A/09246A-24/2
Turn FREQ range potentiometer on governor control unit two turns, counterclockwise.
Start and operate generator set at rated voltage and turn FREQUENCY adjust potentiometer on control panel
Turn FREQ range potentiometer until rated frequency (50, 60 or 400 Hz) is indicated on control panel FRE-
QUENCY meter (HERTZ).
Set load bank for generator set rated load and apply bat. Observe generator set instruments and adjust load
as needed to ensure rated bad is applied.
Set multimeter for DC volts and connect to terminals 11 and 12 of governor control unit (3, FIGURE 4-3).
Adjust LOAD SHARING ADJUST rheostat until multimeter indicates 6 VDC. Disconnect multimeter.
Turn on voltage and frequency recorder and operate at minimum chart speed of 5 mm/see (chart resolution of
0.2 mm/sec). Adjust recorder voltage amplifier for minimum chart resolution of 1.0 volt/mm and frequency devi-
ation of 0.2 Hz/mm.
Adjust GOV GAIN potentiometer on governor control unit as follows:
Turn GOV GAIN potentiometer to its full clockwise position.
Momentarily actuate and turn off LOAD switch on control panel.
Observe strip chart on recorder for frequency oscillation (hunting). If required, slowly turn GOV GAIN
counterclockwise until frequency oscillation disappears.
x. Apply and remove rated load to generator set at 40-second intevals. Repeat this step two more times.
Shut down generator set and turn off recorder.
Examine voltage and frequency strip chart for the following performance criteria:
Frequency regulation shall not exceed 1/4 of one percent of rated frequency.
Frequency short-term stability (30 seconds), frequency will remain constant within a band width equal
to 1/2 of 1 percent rated frequency, without repetitive frequency variations (hunting).
The generator set will reestablish stable ermine operation within two seconds of a sudden load charge
(i.e., from a Ioad to no-load condition) (within one second for 400 Hz units). The maximum transient fre-
quency change above (overshoot) and below (undershoot) the new steady state frequency shall not be
more than 4 percent of rated frequency (not more than 1-½ percent for 400 Hz units).
All required INTEG and LOAD PULSE potentiometer adjustments will be in 10 per-
Adjust INTEG potentiometer on governor control unit clockwise to decrease recovery time of load transients.
Adjust LOAD PULSE potentiometer on governor control unit clockwise to decrease frequency overshoot and
undershoot and to decrease recovery time of overshoot/undershoot transients.
Start generator set.