(8) Repeat paragraphs (5), (6), and (7) above for other
c. Installation. Refer to Operator and Organizational
lights, connecting pin C to pins F, G, H, I, K, L, M, and N.
Maintenance Manual and install the fault indicator.
Section III. CONTROL CUBICLE
3-5. Removal, Disassembly and Repair.
To avoid serious injury to personnel before do-
ing any work in the control cubicle, be sure all
power circuits are disconnected. Never work in
the control cubicle while the engine is running.
Killing voltages are present.
a. Removal. Refer to Operator and Organi-
zational Maintenance Manual and remove the control
b. Disassembly. Refer to Operator and Organizational
Maintenance Manual and disassemble the control cubicle,
See figure 3-3 and disassemble the relay assembly.
(1) Clean all components with low pressure compressed
air, or wipe clean with dry, lint free cloth.
(2) Inspect for broken fuseholders, cracked or broken
lamp holders, damaged meters, broken terminals on com-
ponents, damaged wire insulation, broken wires and bent
or broken connector pins.
(3) Replace any components which show visual damage,
such as cracked or broken meters, broken lamp holders, or
cracked or broken switches and rheostats.
(4) Inspect control panel relay assembly for damage.
Replace component (fig. 3-3) if damage is evident. If any
connections are opened or bared for test purposes, or if any
defective components are replaced, the effected areas and
components must be coated with polyurethane resin to pre-
vent oxidation or other corrosion. The coating must be a
minimum of 0.007 inches and air bubble entry into the ap-
plied polyurethane must be controlled so that the legibility
of component coding and identification is not impaired. The
polyurethane resin to be utilized will correspond to MIL-
I-46058 grade S, Type PUR.
3-6. AC Wattmeter Convertor Testing.
To test the ac wattmeter of the control cubicle proceed as
b. Start the generator set.
c. Vary load and compare the readings of the ac watt-
meter on the set with readings of the master wattmeter.
d. The operating set wattmeter error must not exceed 10
percent of full scale value. If it does, replace the ac watt-
meter. If it does not, proceed to para 3-7.
3-7. Transducer Testing.
To test the control cubicle watt transducer, proceed as
a. Connect the watt transducer to the test equipment
as illustrated in figure 3-4. Use a calibrated % of rating
b. Adjust all autotransformers T1, T2 and T3 to their
c. Close switch S1 and open switches S2 and S3.
d. Energize the power source.
e. Adjust T1 until 600 milliamperes is indicated on am-
meter A1. The % of rating meter of known accuracy should
indicate approximately 33%.
f. Close switch S2 and adjust T2 until 600 milliamperes
is indicated on ammeter A2. The % of rating meter should
indicate approximately 66%.
g. Close switch S3 and adjust T3 until 600 milliamperes is
indicated on ammeter A3. The % of rating meter of known
accuracy should indicate 100%.
h. Replace the thermal watt transducer if it does not
satisfy the above requirements.
i. If the transducer meets the above requirements,
replace the wattmeter.
3-8. AC Ammeter Testing.
To test the ac ammeter of the control cubicle, proceed as
a. Connect a suitable master ac current meter in series
with the set ac current meter.
b. Start the unit and connect a variable load to the output
terminals and compare the readings of the two meters.
c. The generator set ac ammeter error must not be
greater than 2 percent of full scale value. If it is, replace
the ac ammeter.
a. Connect a master 3-phase wattmeter of known
accuracy (1/2 of 1 percent) and a suitable variable load to
the output of terminal lugs of the generator set.