TM 9-4940-549-14&P
Table 4-1. Quaterly Preventive Maintenance Checks and Services-Continued
Item to be Inspected
Procedure
Sequence No.
Welder Controls and Instruments
7
Inspect for damage and loose mounting. With unit
operating check for proper operation. Normal
operating readings are as follows:
AC Voltmeter: . 240-volts.
Frequency Meter: 50-60 hertz.
DC Voltmeter: Terminal voltage.
DC Ammeter: Indicates applied load current not
to exceed 300 amps.
Replace defective controls or instruments.
Engine Controls and Instruments
8
Inspect for damage and loose mounting. With unit
operating check for proper operation. Normal
readings are as follows:
Water temperature gage: 180-195F.
Oil pressure gage: 40-60 psi.
Battery alternator indicator: Pointer to green.
1,800 rpm at 60-hertz.
1,500 rpm at 50-hertz.
Replace defective controls or instruments.
Circuit Breakers
9
Inspect for defective circuit breaker. Replace
defective circuit breaker.
10
Air Pressure Gage
Check for normal gage reading of 125-150 psi.
Clean safety relief valve and adjust to open
at 175 psi as necessary.
4-21
