ARMY TM 9-6115-643-24
AIR FORCE TO 35C2-3-445-22
x. Examine voltage and frequency strip chart for the following performance criteria:
(1) Frequency regulation shall not exceed 1/4 of one percent of rated frequency.
(2) 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).
(3) The generator set will reestablish stable engine operation within two seconds of a sudden load change (i.e.,
from a load to no-load condition) (within one second for 400 Hz units). The maximum transient frequency
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 -1/2 percent for 400 Hz units).
NOTE
All required INTEG and LOAD PULSE potentiometer adjustments will
be in 10 percent increments.
y. Adjust INTEG potentiometer on governor control unit clockwise to decrease recovery time of load transients.
z. Adjust LOAD PULSE potentiometer on governor control unit clockwise to decrease frequency overshoot and un-
dershoot and to decrease recovery time of overshoot/undershoot transients.
aa. Start generator set.
NOTE
Steps u(1) and u(2) are not required when doing step ab.
ab. Repeat steps t through v until generator set meets performance requirements stated in step x.
ac. Apply and remove 75 percent rated load to generator set at 40-second intervals. Repeat this step two more times.
ad. Apply and remove 50 percent rated load to generator set at 40-second intervals. Repeat this step two more times.
ae. Apply and remove 25 percent rated load to generator set at 40-second intervals. Repeat this step two more times.
af. Shut down generator set and turn off strip chart recorder.
ag. Examine voltage and frequency strip chart for the following performance criteria:
(1) Frequency regulation shall not exceed 1/4 of one percent of rated frequency.
(2) 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).
(3) The generator set will reestablish stable engine operation within two seconds of a sudden load change (i.e.,
from a load to no-load condition) (within one second for 400 Hz units). The maximum transient frequency
change above (overshoot) and below (undershoot) the new steady state frequency shall not be more than four
percent of rated frequency (not more than 1-1/2 percent for 400 Hz units).
ah. Disconnect load bank and close load terminal board access door.
ai. Disconnect frequency counter, and voltage and frequency recorder from voltage reconnection terminal board.
aj. Install voltage reconnection terminal board cover and close output box access door.
4.2.4
Replacement.
a. Remove governor control unit, paragraph 2.60.2.
b. Install new governor control unit, paragraph 2.60.3.
c. Perform adjustment of governor control unit, paragraph 4.2.2.
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