ARMY TM 9-6115-644-24
AIR FORCE TO 35C2-3-446-12
MARINE CORPS TM 09249A/09246A-24/2
ad.
ae.
af.
ag.
ah.
ai.
NOTE
Steps w(1) and w(2) are not required when doing step ad.
Repeat steps v through x until generator set meets performance requirements stated in step z.
Apply and remove 75 percent rated load to generator set at 40-second intervals. Repeat this step two more
times.
Apply and remove 50 percent rated load to generator set at 40-second intends. Repeat this step two more
times.
Apply and remove 25 percent rated load to generator set at 40-second intervals. Repeat this step two more
times.
Shut down generator set and turn off strip chart recorder.
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 fre-
quency change above (ovemshoot) 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).
aj. Disconnect load bank and dose Ioad terminal board access door.
ak. Disconnect frequency counter, and voltage and frequency recorder from voltage reconnection terminal board.
al. Install voltage reconnection terminal board cover and dose output box access door.
4-3-4 Replacement.
a.
Remove governor control unit, paragraph 2-61-2.
b. Install new governor control unit, paragraph 2-61-3.
c.
Perform adjustment of governor control unit, paragraph 4-3-3.
4-4 CONTROL BOX HARNESS.
4-4-1 Removal.
a. Shutdown generator set.
b. Open battery access door and disconnect negative battery cable.
c.
Remove control box assembly, paragraph 2-19-2.
d. Remove voltage sensing relay, paragraph 2-59-3.
e.
Remove relays, paragraph 2-60-3.
4-10
