Miller Electric Big 40 CAT Owner's Manual page 57

B. Welding − CC/CV 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.
Voltage/Amperage control does not
work when welding in Stick mode.
Low weld output.
Electrode sticks to the workpiece more
frequently during low voltage (short arc
length) conditions.
Low open-circuit voltage.
No remote fine amperage or voltage
control.
Constant speed wire feeder does not
work.
Low CV weld output.
Place Process/Contactor switch in a Electrode Hot position, or place switch in a Remote position and
connect remote contactor to optional Remote 14 receptacle RC14 (see Sections 5-11 and 7-1).
Check position of Ampere Range switch.
Check position of optional Polarity switch or Polarity/AC switch.
Reset circuit breaker CB11 (see Section 9-8).
Reset circuit breaker CB5 (see Section 9-8). Check for faulty remote device connected to RC14.
Check and secure connections to Remote 14 receptacle RC14 (see Section 5-11).
Have Factory Authorized Service Agent check connector board PC6 and connections.
Check fuse F2, and replace if open (see Section 9-8). Have Factory Authorized Service Agent check
brushes and slip rings, weld excitation circuit, field current regulator board PC1, and the rotor.
Disconnect equipment from generator power receptacles during start-up.
Check fuses F1 and F2, and replace if open (see Section 9-8). Have Factory Authorized Service Agent
check integrated rectifier SR1, capacitor C9, field current regulator board PC1, and the rotor.
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 position of Ampere Range switch and Voltage/Amperage Adjust control.
Check engine speed, and adjust if necessary.
Have Factory Authorized Service Agent check field current regulator board PC1.
Place Ampere Range switch in lower range. Voltage/Amperage control does not work with Ampere
Range switch in highest range.
Check engine speed, and adjust if necessary.
Check fuses F1 and F2, and replace if open (see Section 9-8). Have Factory Authorized Service Agent
check integrated rectifier SR1, capacitor C9, field current regulator board PC1, and the rotor.
Circuit breaker CB4 may be open. CB4 automatically resets when the fault is corrected (see Section 9-8).
Have Factory Authorized Service Agent check transformer T1 and integrated rectifiers SR4 and SR5.
Check engine speed, and adjust if necessary.
Place Voltage/Amperage Adjust switch in Remote position.
Check and secure connections to Remote 14 receptacle RC14 (see Section 5-11).
Repair or replace remote control device.
Reset circuit breaker CB5 or CB6 (see Section 9-8).
Check and secure connections to Remote 14 receptacle RC14 (see Section 5-11).
Repair or replace wire feeder.
Set Ampere Range switch to highest range.
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Remedy
OM-4406 Page 51