Miller Electric Big Blue 500 PT Owner's Manual page 52

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.
OM-4429 Page 48
Place Process/Contactor switch in a Weld Terminals Always On position, or place switch in a Remote
On/Off Switch Required 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 supplementary protector CB11 (see Section 9-7).
Reset supplementary protector CB5 (see Section 9-7). 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 9-7). 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 9-7). Have Factory Authorized Service Agent
check integrated rectifier SR1, capacitor C9, field current regulator board PC1, and the rotor.
Reset supplementary protector CB12. Have Factory Authorized Service Agent check diode D1 (see Sec-
tion 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 position of Ampere Range switch and Voltage/Amperage Adjust control.
Check engine speed, and have Factory Authorized Service Agent adjust if necessary.
Have Factory Authorized Service Agent check field current regulator board PC1, and PC1 voltage feed-
back circuit.
Place Ampere Range switch in lower range. Voltage/Amperage control does not work with Ampere
Range switch in highest range.
Check position of Ampere Range switch and Voltage/Amperage Adjust control.
Check engine speed, and have Factory Authorized Service Agent 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, field current regulator board PC1, and the rotor.
Circuit breaker CB4 may be open. CB4 automatically resets when the fault is corrected (see Section 9-7).
Have Factory Authorized Service Agent check transformer T1 and integrated rectifiers SR4 and SR5.
Check engine speed, and have Factory Authorized Service Agent adjust if necessary.
Check position of Process/Contactor switch.
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.
Have Factory Authorized Service Agent check PC1 sensing leads (36 and 37), and connections.
Reset supplementary protector CB5 or CB6 (see Section 9-7).
Remedy