TM 9-4940-549-14&P
Table 4-2. Troubleshooting-Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
DYNAMOTOR-WELDER
Dynamotor-Welder Noisy.
1.
Inspect for damaged bearings.
Remove and disassemble the welder.
Replace damaged bearings (para. 13-9).
2.
Dynamotor-Welder Does Not Develop Welding Current.
Check the brush tension, and for burned or worn brushes.
Step 1.
Adjust brush spring tension or replace brushes (para. 13-4).
Step 2.
Remove and disassemble the welder and inspect for the interpole
coils, compound coils, field coils, commutator, DC resistance
element, and the armature.
Remove and correct as necessary. Clean commutator. Adjust exciter
brush tension or replace brushes (paras. 13-1 through 13-10).
Dynamotor-Welder Does Not Furnish Alternating Current.
Remove and disassemble welder to inspect the rotating coils for excitation
voltage, damaged field, and/or defective stator coils.
Repair, replace, or adjust brush tension as necessary (paras. 13-1
through 13-10).
4.
Dynamotor-Welder Will Not Function As A Motor (External Power).
Remove and disassemble welder to inspect the stator coils, armature, and
main contactor switch.
Repair or replace as necessary (paras. 13-1 through 13-10).
Dynamotor-Welder Exciter Does Not Furnish Excitation Voltage Or Voltage
5.
Is Below Required Level.
Step 1.
Inspect for burned and badly worn brushes.
Adjust brush spring tension or replace brushes (para. 13-4).
Remove and disassemble welder to check for dirty commutator
Step 2.
and defective field coils and armature.
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