Machine has low output when in tig 4-step mode, Troubleshooting & repair, Troubleshooting guide – Lincoln Electric SQUARE WAVE TIG 255 SVM100-A User Manual
Page 53: Caution
SQUARE WAVE TIG 255
F-12
TROUBLESHOOTING & REPAIR
Observe Safety Guidelines
detailed in the beginning of this manual.
TROUBLESHOOTING GUIDE
PROBLEMS
(SYMPTOMS)
Machine has low output when in
TIG 4-Step Mode.
Weak high frequency - machine
has normal welding output.
The display shows zero amps, but
indicates open circuit voltage
(approximately 53V). The arc start
switch or amptrol is not actuated.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
1.
Machine must be in “Local”
Control Mode when 4-Step is
used.
1.
Spark gap may be misadjusted.
Check and reset per
maintenance instructions.
2.
Improper shielding gas flow.
Adjust for a flow of 10 to 30
CFH (4.7 to 14.1 l/min.) for
most applications.
3.
Work and electrode cables in
poor condition allowing high
frequency to “Leak Off”. Use
good quality cables with a high
natural rubber content, such
as Lincoln Stable Arc Cable.
Cables should be as short as
possible.
1.
The arc start switch or amptrol
may be defective. There should
not be any continuity between
pins “D” and “E” on the arc start
cable connector, unless the
unit is actuated.
2.
If an amptrol is not being used,
the machine must be in the
Local Control Mode.
RECOMMENDED
COURSE OF ACTION
Machine controls may be set incor-
rectly.
Contact The Lincoln Electric
Service Department (216) 383-
2531 or 1-800-833-9353 (WELD).
1.
Check for an open or arcing
high frequency component.
Replace as required.
(Examples. R3, R4, C2.) Refer
to wiring diagram.
2.
If spark is weak at the spark
gap check or replace high fre-
quency circuit. ( Examples. T3,
C3, L3, L4.)
1.
Check Trigger circuit. See Arc
Start Trigger Circuit Test.
2.
Control board may be faulty.
Replace.
TIG MODE PROBLEMS
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.
CAUTION