ARMY TM 9-6115-643-24
AIR FORCE TO 35C2-3-445-22
If generator set has not shut down at upper limit of frequency noted in step i, proceed as follows:
(1) Turn FREQ range potentiometer counterclockwise until frequency counter indicates midrange of overspeed
trip frequency (Example: 66 Hz for MEP804A).
(2) Turn OVERSPD control potentiometer on governor control unit counterclockwise until generator set shuts
(3) Activate OVERSPD RESET switch.
(4) Repeat steps h and i.
If generator set shuts down prior to reaching lower limit of frequency noted in step i, proceed as follows:
(1) Turn OVERSPD control potentiometer clockwise one turn for each hertz generator set shut down prior to lower
(2) Activate OVERSPD RESET switch.
(3) Repeat steps h and i.
Actuate OVERSPD RESET switch.
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 to
Turn FREQ range potentiometer until rated frequency (50,60 or 400 Hz) is indicated on control panel FREQUEN-
CY meter (HERTZ).
Set load bank for generator set rated load and apply load. Observe generator set instruments and adjust load as
needed to ensure rated load is applied.
Set multimeter for DC volts and connect to terminals 11 and 12 of governor control unit (3, FIGURE 4-1).
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 mrn/sec (chart resolution of 0.2
mm/sec). Adjust recorder voltage amplifier for minimum chart resolution of 1.0 volt/mm and frequency deviation
of 0.2 Hz/mm.
Adjust GOV GAIN potentiometer on governor control unit as follows:
(1) Turn GOV GAIN potentiometer to its full clockwise position.
(2) Momentarily actuate and turn off LOAD switch on control panel.
(3) Observe strip chart on recorder for frequency oscillation (hunting). If required, slowly turn GOV GAIN counter-
clockwise until frequency oscillation disappears.
Apply and remove rated load to generator set at 40-second intervals. Repeat this step two more times.
Shut down generator set and turn off recorder.