TM 55-4920-212-15
Section IV. TROUBLESHOOTING
101. Use of Troubleshooting Section
105. Electrical Equipment Will Not Start
This section contains troubleshooting information useful to
Probable cause
Possible remedy
second echelon personnel in diagnosing and correcting
Power cord disconnected ....................... Check rear power outlet for
unsatisfactory operation or failure of the shop set or any
proper installation of
of the components.
power cord of auxiliary
power source
102. Procedure
One or more circuit break-
ers inoperative. ................................... Check circuit breakers and
Troubleshooting is a systematic isolation of defective
replace as necessary.
components by means of an analysis of the shop set
Safety switch inoperative ........................ Replace safety switch
trouble symptoms, testing to determine the defective
Corroded prong or loose
connection at power
component, and applying the remedies. To correct
receptacle .......................................... Clean prong and check em-
malfunctioning of equipment, the probable cause should
nectors and plug for
be systematically isolated in accordance with instructions
tightness.
in paragraphs 103 through 113.
Cause beyond repair
scope of operator . ............................. Notify supporting field
103.
Electrical Equipment Operates at Slow or
maintenance unit.
Reduced Speed
106. Pneumatic Equipment Operates at Slow or
Reduced Speed
Probable cause
Possible remedy
Loose connectors ................................... Tighten connectors.
Probable cause
Possible remedy
Low voltage............................................. Check incoming voltage.
Low air pressure ..................................... Check air pressure gauges
Improper source of
and regulators; adjust as
voltage-............................................... Check source voltage for
necessary.
specified requirements.
Leak in air line(s) or
Cause beyond repair
loose connector()................................ Check air pressure at equip-
scope of operator. .............................. Notify supporting field
ment; retrace air line(s);
maintenance unit.
check for eaks and loom
104. Electrical Equipment Stops During Operation
connector(s).
Cause beyond repair scope
Probable causePossible remedy
of operator .......................................... Notify supporting field
Power source
maintenance unit
disconnected. ..................................... Check external power cable,
107. Pneumatic Equipment Stops During Operation
cords and circuit breakers
Overheating of
Probable cause
Possible remedy
equipment .......................................... Check equipment for speed
Failure of source of power ...................... Check compressor for at
setting and voltage as ne-
tion, check incoming axui-
cessary. Allow equipment
Iiary line for pressure
to cool and restart.
Overloading ............................................ Reduce feed, pressure on
Overloading ............................................ Adjust feed or speed of
work, or speed as neces-
equipment as necessary.
sary
Cause beyond repair
Cause beyond repair
scope of operator ............................... Notify supporting field
scope of operator . ............................. Notify support field
maintenance
unit
maintenance unit.
108. Pneumatic Equipment Will Not Start
Probable cause
Possible remedy
Source of power
disconnected . .................................... Check connections at points
of installation
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