Trouble Cause What to do | Lincoln Electric IM402-B guide

TROUBLE	CAUSE		WHAT TO DO

A. Welder will not weld.	1.	Line switch not turned “On”.	1.	Place line switch in “On” posi-
		Supply line fuse blown.		tion. Replace. (Look for reason
				for blown fuse first).
	2.	Power circuit dead.	2.	Check supply line voltage.
	3.	Broken power lead.	3.	Repair.
	4.	Wrong voltage.	4.	Check voltage against rating
				plate. Check reconnect panel
				jumper.
	5.	Electrode or work lead loose or	5.	Tighten and repair connections.
		broken.
	6.	Open transformer circuit.	6.	Send to repair shop to have coils
				replaced.
	7.	Polarity switch not centered.	7.	Center switch handle on DC(+),
				DC(-), or AC.

B. Welder welds, but soon stops	1.	Proper ventilation hindered.	1.	Make sure all case openings are
welding (DC only).				free for proper circulation of air.
	2.	Welder loaded beyond rating.	2.	Operate at normal current and
				duty cycle consistent with rating.
	3.	Fan motor inoperative.	3.	Check leads and motor bear-
				ings. Fan motor can be tested
				on 115V line; with welder on,
				voltage across fan motor should
				be approximately 115V.
	4.	Poor internal connections.	4.	Check for loose or hot connec-
				tions and tighten.
	5.	Excessive dust accumulation in	5.	Blow out welder with low pres-
		welder.		sure.

6. Bi-metallic thermostat dirty.

6. Carefully clean in naptha.

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TROUBLE