TM 9-4940-568-34
5-135
HAZARDOUS VOLTAGE
Touching un-insulated high voltage parts inside the control and power output boxes can
result in severe personal injury or death. Measurements and adjustments must be done
with care to avoid touching high voltage parts.
For your protection, stand on a dry wooden platform or rubber insulating mat, make sure
your clothing and shoes are dry, remove jewelry and use tools with insulated handles.
(3)
Measure voltage across lead pairs P2-P3, P3-P4, and P4-P2. Voltage should be at least 150 VAC for 50
Hz sets and at least 180 VAC for 60 Hz sets, and should be approximately the same for each set of leads.
If the voltages are low or uneven, check all the leads and connections between the voltage regulator and
the PMG and repair as necessary before disassembling the PMG. Note the connections at the auxiliary
terminal board in the power output box.
(4)
Stop the set and measure electrical resistance across lead pairs P2-P3, P3-P4, and P4-P2 with a
Wheatstone bridge or digital ohmmeter. Each winding should have a resistance of approximately 4.4
ohms.
END OF TASK
