Lincoln Electric R3R-500 User Manual

Observe Safety Guidelines

detailed in the beginning of this manual.

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  Call
216-383-2531 or 1-800-833-9353.

Poor arc characteristics.

1.  Make sure the correct weld pro-

cedures are being used.
(Electrode, Polarity, etc.)

2.  Check the welding cables for

loose or faulty connections.

1.  Perform the SCR/Diode

2.  Perform the Main Transformer

3.  The control board may be

faulty.  Replace.

The welding arc is variable and
sluggish.

1.  Check the input voltage at the

R3R, making sure the correct
voltage and all three phases are
being applied to the machine.

2.  Make sure the welding

process is correct for the
machine settings.

3.  Check the welding cables for

loose or faulty connections.
Also make sure the cables are
sized correctly for the welding
current.

1.  Perform the SCR/Diode

2.  Perform the Main Trans-

3.  The control board may be

faulty.  Replace.