Section 9 − Troubleshooting; Troubleshooting - Miller Big Blue 800 DUO PRO Owner's Manual

SECTION 9 − TROUBLESHOOTING

9-1. Troubleshooting

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Also see Voltmeter/Ammeter help displays to assist in troubleshooting weld problems (see Section 8-9). Also see Engine Information Display to
assist in troubleshooting engine related problems (see Section 12).
A. Welding
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.
Low open-circuit voltage.
High open−circuit cvoltage with VRD
switch S5 On.
No remote fine amperage or voltage
control.
.
Complete Parts List available at www.MillerWelds.com
Place Process/Contactor switch in an Electrode Hot position, or place switch in a Remote On/Off Re-
quired position and connect remote contactor to Remote 14 receptacle (see Sections 5-15).
Reset supplementary protector CB3 (see Section 8-8).
Reset supplementary protector CB9 (see Section 8-8). Check for faulty remote device connected to
Remote 14 receptacle.
Check and secure connections to Remote 14 receptacle (see Section 5-15).
If VRD switch S5 is On, check voltage feedback wires at output terminals and have Factory Authorized
Service Agent check Main Control boards PC1 and PC21.
Have Factory Authorized Service Agent check filter board PC5 and connections.
Check fuse F2, and replace if open (see Section 8-8). Have Factory Authorized Service Agent check
brushes and slip rings, weld excitation circuit, and the rotor.
Disconnect equipment from generator power receptacles during start-up.
Reset supplementary protector CB4 (see Section 8-8).
Check fuses F1 and F2, and replace if open (see Section 8-8). Have Factory Authorized Service Agent
check integrated rectifier SR2, capacitor C6, 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 Voltage/Amperage Adjust control.
Have Factory Authorized Service Agent check voltage feedback circuit.
Check position of Voltage/Amperage Adjust control.
Check fuses F1 and F2, and replace if open (see Section8-8). Have Factory Authorized Service Agent
check integrated rectifier SR2, capacitor C6, and the rotor.
Place VRD switch S5 in off position and try welding. If machine operates normally, have Factory Autho-
rized Service Agent check S5 and Main Control Board PC1 and PC21.
Check position of VRD switch.
Check position of Process/Contactor switch.
Have Factory Authorized Service Agent check IGBT modules PM1, PM2, PM21 and PM22; check and
replace Main Control boards PC1 and PC21.
Check and secure connections to Remote 14 receptacle (see Section 5-15).
Repair or replace remote control device.
Have Factory Authorized Service Agent check current sensing devices, and connections.
Remedy
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