EXCEL-ARC 500, 6045
August 22, 2005
5-3
6. Solid-state contactor operates, but welding machine
will not deliver welding current, and open circuit
voltage is present at the output when gun switch is
depressed.
A. No ground connections at work.
1) Make connections.
B. Welding cables not connected.
1) Make connections.
7. Voltage/amps dial does not control welding voltage.
A. Potentiometer burned out.
1) Replace.
B. Loose connections in voltage control circuit.
1) Check connections.
C. Control circuit board failure.
1) Replace control board.
8. Fan not operating (also see causes and remedies
under “Welding machine will not start”).
NOTE
Fan will not operate until rectifier heats up.
A. Motor failed.
1) Replace or repair.
B. Broken lead or connection to fan motor.
1) Repair wiring.
C. Blown circuit breaker on rear panel of welding
machine.
1) Reset circuit breaker. 115-volt receptacle
may be overloaded.
9. Operator gets shock when welding machine case,
ground cable, work, or work table is touched.
A. Case of welding machine not grounded.
1) Ground welding machine case.
B. Work table and work not grounded.
1) Ground work and work table to plant
ground.
10.Abnormal current fluctuation, voltage nearly
constant.
A. Irregular wire feed speed.
1) See welding head manual.
B. Inadequate shielding of arc by flux or gas.
1) Increase shielding by trial and error. See
welding head manual.
C. Wire feed rate too slow.
1) Increase wire feed. See wire burn-off rate
charts.
D. Too much shielding gas.
1) Decrease by trial and error. See welding
head manual.
E. Loose cable connections.
1) Check for overheated connections and
tighten.
F. Welding contact tube (tip) on wire feeder
makes poor contact with electrode.
1) Check contact tube hole size and replace
with proper tube.
11.Contactor fails to open.
A. Contactor contacts sticking.
1) Clean contacts.
12.Very noticeable, rough, sputtering arc. Loss of
control and burnback. Minor starting problems.
A. Control circuit board failure.
1) Replace Control P.C. Board.
