Lincoln Electric SQUARE WAVE TIG 255 SVM100-A Manual Do Utilizador

Observe Safety Guidelines

detailed in the beginning of this manual.

Stick electrode “Blasts Off” when
arc is struck.

Cannot adjust AC Wave Balance
when welding in the Stick Mode.

Machine welds at a very low output
regardless of the preset current set-
ting - arc is stable.

Variable or sluggish welding arc
when welding in the Stick Mode.

1.

Weld current is set too high 
for recommended electrode 
size.  Reduce preset current 
adjustment.

1.

This is a normal condition.  
Wave balance keys are 
automatically disabled in the 
Stick Mode.

1.

If welding in the Remote 
Control Mode, the remote 
amptrol may be defective or 
not installed properly.

2.

If the output is low when the 
machine is in the Local 
Control Mode, the problem 
could be internal to the 
machine.

1.

Check work and electrode 
cables for loose or poor 
connections.

2.

The weld cables may be too 
small or too long to permit the 
desired current to flow.

3.

The preset current adjustment 
may be set too low.

1.

Possible faulty SCR bridge.
See Static and Active SCR
Tests.

2.

Control board may be faulty.
Replace.

None

1.

Check the SCR bridge.  See
Static and Active SCR Tests.

2.

Check polarity switch (S2)
connections and operation.

3.

Check the control transformer
(T2). See Control Transformer
Voltage Test.

4.

The Control board may be
faulty.  Replace.

1.

Check polarity switch (S2) for
wear or loose connentions.

2.

Check interior connections of
the heavy current carrying
leads.

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