ARMY TM 9-6115-643-24
AIR FORCE TO 35C2-3-445-22
4.1
4.1.1
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
l.
CHAPTER 4
DIRECT SUPPORT MAINTENANCE INSTRUCTIONS
Section I. MAINTENANCE OF CONTROL BOX ASSEMBLY
AC VOLTAGE REGULATOR.
WARNING
High voltage is produced when this generator set is in operation.
proper operation could result in personal injury or death.
Testing. (Regulator, P/N: 122-3054 For MEP-804A Generator Set).
Shut down generator set.
Open output box access door.
lm-
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 following
steps. Otherwise, AC voltage regulator (2, FIGURE 4-1) 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 multimeterto terminal
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.
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 210
to 280 VAC.
Shut down generator set.
Disconnect wire 137A from terminal 5 of AC voltage reaulator. 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
TABLE 4-1. Voltage Adjustment Range (MEP-804A)
Voltage Reconnection Terminal Board Position
Adjustment Range
120/208
197-240 volts
240/416
395-480 volts
m.
n.
o.
SELECT switch in 60 Hz position, and approximately 0 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.
If steps h, j, and I are as indicated above, AC voltage regulator is defective and must be replaced.
Connect all wires previously disconnected.
Close output box access door.
4-1
