rheostat. Connection is made from the voltage regulator
increase or decrease voltage.
to the box by a contact panel assembly.
Ground test. Connect a 28-volt, direct-
current, test lamp between the regulator
box and each receptacle pin in turn. In no
186. Generator Voltage Regulator Assembly Removal
case should a closed circuit be indicated
(lamp should not light).
Remove the generator voltage
Operational test and adjustment.
regulator assembly (TM 5-3825-213-20).
Connect the voltage
(a) Test set-up.
b. Disassembly. Disassemble the generator voltage
regulator into the test circuit described
regulator in numerical sequence as illustrated on figures
187. Generator Voltage Regulator Assembly
Cleaning, Inspection, and Repair
Never allow the voltage to exceed 32
volts during these tests, or the
(1) Clean the regulator box and cover
assembly with compressed air.
otherwise stated, a battery must be
(2) Clean all other parts in an approved
connected in the load circuit at all
times during tests.
b. Inspection and Repair.
(1) Inspect the main relay contacts for burned
or pitted condition.
Setting is defined as a form of
cracks or breaks. Replace defective parts.
lapping the carbons together by ra-
(3) Inspect for loose connections and damaged
pid vibration. This is accomplished
hardware. Replace defective parts.
by placing the voltage regulator in a
(4) Inspect all other parts for defective
circuit which allows the carbon disk
condition. Replace all worn, damaged, or
to vibrate under controlled condi-
tions. The vibration can be heard
through an earphone connected as
188. Generator Voltage Regulator Assembly
Reassembly, Testing, Adjusting, and
Remove the cover assembly (par.
45), and connect for setting the
carbon pile as shown on figure
a. Reassembly. Reassemble the generator voltage
51. Adjust the variable resistor
regulator assembly in the reverse of numerical sequence
reads 12 to 14 volts. A crackle
b. Testing and Adjusting.
in the earphone or an erratic
(1) Load relay assembly closing voltage
vibration indicates a loose
adjustment. With the cover assembly off,
adjustment of carbon pile.
connect a 24-volt battery, variable resistor
Remove the disk and tube
(0-100 ohms, 5 watts), and 0 to 50
tighten the carbon pile by
cable electrical receptacle (17, fig. 2).
turning the contact screw
Slowly increase the voltage by adjusting the
variable resistors, until the relay closes.
just enough to eliminate the
The correct closing voltage is 17 to 18
crackle and leave a distinct
volts. Adjust the voltage, if necessary, by
turning the adjusting nut (31, fig. 3) to