Troubleshooting, Caution – Lincoln Electric DC-650 PRO IM463-A User Manual
Page 21
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21
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TROUBLE
E.
Machine has low output and
no control.
F.
Machine does not have
maximum output.
G. Machine will not shut off.
H. Variable or sluggish welding
arc.
CAUSE
1.
Output control Local/Remote
switch in wrong position.
2.
Output control switch faulty.
3.
Fault in leads 75,76, or 77.
4.
Faulty Control P.C. Board.
5.
Output control potentiometer
circuit open (lead 75).
1.
One input fuse blown.
2.
One phase of main transformer
open.
3.
Faulty Control P.C. Board.
4.
Output control potentiometer.
5.
Output control potentiometer
lead 75 open.
6.
Defective main SCR bridge.
1.
Input contactor contacts frozen.
2.
Defective On/Off switch, S-1.
1.
Poor work or electrode
connection.
2.
Welding leads too small.
3.
Welding current or voltage too
low.
4.
Leads or connections open in control
circuit.
5.
LN-9/NA-5 switch in wrong position.
WHAT TO DO
1.
Check position of switch.
2. Check switch and replace if faulty.
3.
Check wiring.
4.
Replace. See P.C. Board
Troubleshooting Procedure.
5.
Check and replace
potentiometer if faulty. Check
wiring of lead #75.
1.
Check and replace if blown
after checking for reason for
blown fuse.
2.
Check for open and repair.
3.
Replace. See P.C. Board
Troubleshooting Procedure.
4.
Check and replace if faulty.
5.
Check and repair broken leads.
6.
Check and replace if defective.
1.
Check and replace if
necessary.
2.
Replace.
1.
Check & clean all connections.
2.
Check table in instruction manual.
3.
Check procedures for
recommended settings.
4.
Check & replace if defective.
5.
Only connect one pair of
negative studs to the work.
TROUBLESHOOTING
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your
Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
CAUTION