TROUBLESHOOTING

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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Lincoln Electric IM402-B manual Trouble Cause What to do