Troubleshooting - Miller Electric Big Blue 602P Owner's Manual

9-9. Troubleshooting

A. Welding − CC Models
Trouble
No weld output; generator power output
okay at ac receptacles.
No weld output or generator power out-
put at ac receptacles.
Erratic weld output.
High weld output.
Low weld output.
Electrode sticks to the workpiece more
frequently during low voltage (short arc
length) conditions.
Low open-circuit voltage.
Maximum weld output only in each
ampere range (with Stick/TIG Selection
switch in Stick position).
No remote fine amperage control.
Check position of Ampere Range switch.
Check position of optional polarity switch.
Place Amperage Adjust switch in Panel position, or place switch in Remote position and connect remote
control to Remote Amperage Adjust receptacle RC13 (see Sections 5-10 and 6-1).
Check and secure connections to Remote Amperage Adjust receptacle RC13 (see Section 5-10).
Check fuse F2, and replace if open (see Section 9-7). Have Factory Authorized Service Agent check inte-
grated rectifier SR2 and the rotor.
Have Factory Authorized Service Agent check brushes and slip rings, and field excitation circuit.
Disconnect equipment from generator power receptacles during start-up.
Check fuses F1 and F2, and replace if open (see Section 9-7). Have Factory Authorized Service Agent
check integrated rectifier SR1, capacitor C9, integrated rectifier SR2, and the rotor.
Reset circuit breaker CB12. Have Factory Authorized Service Agent check diode D1 (see Section 9-7).
Have Factory Authorized Service Agent check brushes and slip rings, and field excitation circuit.
Check and tighten connections inside and outside unit.
Be sure connection to work piece is clean and tight.
Use dry, properly stored electrodes.
Remove excessive coils from weld cables.
Have Factory Authorized Service Agent check brushes and slip rings.
Check engine speed, and adjust if necessary.
Have Factory Authorized Service Agent check OCV control circuit.
Check engine speed, and adjust if necessary.
Check fuses F1 and F2, and replace if open (see Section 9-7). Have Factory Authorized Service Agent
check integrated rectifier SR1, capacitor C9, integrated rectifier SR2, and the rotor.
Circuit breaker CB4 may be open. CB4 automatically resets when the fault is corrected (see Section 9-7).
Have Factory Authorized Service Agent check transformer T1 and integrated rectifiers SR4 and SR5.
Check engine speed, and adjust if necessary.
Have Factory Authorized Service Agent check control relay CR7.
Place Amperage Adjust switch in correct position.
Check and secure connections to Remote Amperage Adjust receptacle RC13 (see Section 5-10).
Reset circuit breaker CB11 (see Section 9-7). Have Factory Authorized Service Agent check control relay
CR7.
Repair or replace remote control device.
Have Factory Authorized Service Agent check OCV control circuit.
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Remedy
OM-491 Page 43