ARMY TM 9-6115-644-24
AIR FORCE TO 35C2-3-446-12
MARINE CORPS TM 09249A/09246A-24/2
CHAPTER 4
DIRECT SUPPORT MAINTENANCE INSTRUCTIONS
Section I. MAINTENANCE OF CONTROL BOX ASSEMBLY
4-1 AC VOLTAGE REGULATOR.
WARNING
High voltage is produced when this generator set is in operation. Improper operation
could result in personaI injury or death.
4-1-1 Testing (Regulator,
P/N: 112-3055 For MEP-805A Generator Set).
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
l.
m.
Shut down generator set.
Open output box access door.
Note position of voltage reconnection terminal board and set FREQUENCY SELECT switch to 60 Hz position.
Start generator set and turn VOLTAGE adjust potentiometer to ensure the adjustment ranges on TABLE 4-1 are
met, depending on position of voltage reconnection terminal board.
Shut down generator set.
If no voltage or Iow voltage was indicated, or voltage adjustment range could not be achieved, perform the follow-
ing steps. Otherwise, AC voltage regulator (2, FIGURE 4-3) is serviceable.
Disconnect wire 141 A from terminal 1 of AC voltage regulator.
Set multimeter for DC volts and connect positive lead to wire 141A. Connect negative lead of multimeter to termi-
nal 3 of AC voltage regulator. Start generator set and operate at rated frequency. Move and hold MASTER
SWITCH in START position. Multimeter should indicate between 4 and 12 VDC. If no voltage, proceed to trou-
bleshooting, Governor Control Unit, paragraph 4-2.
Shut down generator set. Isolate wire 141A.
Set multimeter for AC volts and connect to terminals 10 and 11 of AC voltage regulator. Start generator set and
operate at rated frequency. Move and hold MASTER SWITCH in START position. Multimeter should indicate
280 to 380 VAC. If no voltage or low voltage is indicated in step k above, proceed to troubleshooting the transfomner,
paragraph 4-12.
Shut down generator set.
Disconnect wire 137A from terminal 5 of AC voltage regulator. Set multimeter for ohms and connect positive lead
to wire 137A and negative lead to terminal 4 of AC voltage regulator. Move VOLTAGE adjust potentiometer to
full counterclockwise position. Multimeter should indicate approximately 3,000 ohms with FREQUENCY SE-
LECT switch in 80 Hz position, and approximately O ohms with FREQUENCY SELECT switch in 50 Hz position.
Move VOLTAGE adjust potentiometer clockwise slowly while observing multimeter. Multimeter should increase
smoothly to approximately 10,000 ohms.
Place FREQUENCY Select Switch in 60Hz position.
4-1
