Lincoln Electric AC-1200 manual TROUbLESHOOTING

E-3 TROUbLESHOOTING E-3

PRObLEMS

(SYMPTOMS)

POSSIbLE

CAUSE

RECOMMENDED

COURSE OF ACTION

Welder welds at max. only no con- trol.

Diodes or SCR’s	on heat sink Determine cause if possible and
assemblies shorted.	replace shorted device.

Shorted or grounded current controll Replace rheostat. rheostat.

Output By-Pass Capacitors open or Replace or reconnect. disconnected.

Free wheeling diode open or discon- Replace or reconnect. nected.

P.C. board components failed.	Determine cause if possible and
	replace P.C. board.

Contacts chatter.

Low supply line voltage.

Check with Power Company.

Faulty contactor.

Repair or replace.

CAUTION

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.

IDEALARC® AC-1200