E-3

 

TROUBLESHOOTING

 

E-3

 

 

 

 

 

 

 

Observe all Safety Guidelines detailed througout this manual

 

 

 

 

 

 

 

PROBLEMS

 

POSSIBLE CAUSE

 

RECOMMENDED

 

(SYMPTOMS)

 

 

COURSE OF ACTION

 

 

 

 

 

 

 

 

 

 

 

 

 

FUNCTION PROBLEMS

 

 

 

 

 

 

 

C. Machine input contactor closes

1.

Electrode or work lead loose or

1.

Repair connections.

but has no or low output. Open

 

broken.

 

 

circuit voltage should be 67 to 71

 

 

 

 

volts.

2.

Open transformer primary or

2.

Repair.

 

 

 

secondary circuit.

 

 

 

 

3.

Supply line fuse blown.

3.

Replace blown fuse – check fuse

 

 

 

 

 

size.

 

 

4.

Input line grounded causing

4.

Repair input to machine.

 

 

 

single phase input.

 

 

 

 

5.

Input leads not connected to

5.

Connect input lead.

 

 

 

contactor.

 

 

 

 

6.

Latching resistor, R3, open.

6. a. Replace.

 

 

 

 

 

b. Check leads to the resistor

 

 

 

 

 

and repair if defective.

 

 

7.

Control circuit problems.

7.

See Troubleshooting Procedures

 

 

 

 

 

– Power Silicon Controlled

 

 

 

 

 

Rectifier.

 

 

 

 

 

D. Machine has maximum output

1.

Possible defective power SCR.

1.

Remove all gate leads G1, G2

but no control.

 

 

 

and G3 at PC board connector

 

 

 

 

 

J4. If welder has any open circuit

 

 

 

 

 

voltage, power SCR is defective.

 

 

 

 

 

See Troubleshooting Procedures

 

 

 

 

 

Section J.

 

 

2.

Possible defective control board.

2. See PC board Troubleshooting

 

 

 

 

 

Procedures Section A

 

 

 

 

 

 

 

 

 

 

 

 

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® R3R 375-I, 500-I AND 600-I

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Lincoln Electric R3R 500-I, R3R 375-I manual Function Problems