Gas Flow Problems; Welding Problems - Lincoln Electric SP-100 Service Manual

F-7
Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
Low or no gas flow when gun
trigger is pulled. Wire feed, weld
output and fan operate normally.
PROBLEMS
(SYMPTOMS)
Arc is unstable – Poor starting
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.
SP-100
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)

GAS FLOW PROBLEMS

1. Check gas supply, flow regulator
and gas hoses.
2. Check gun connection to
machine for obstruction or leaky
seals.
POSSIBLE AREAS OF
MISADJUSTMENT(S)

WELDING PROBLEMS

1. Check for correct input voltage
to machine – 115 vac.
2. Check for proper electrode
polarity for process.
3. Check gun tip for wear or dam-
age – Replace.
4. Check for proper gas and flow
rate for process.
5. Check work cable for loose or
faulty connections.
6. Check gun for damage or
breaks.
CAUTION
TROUBLESHOOTING GUIDE
RECOMMENDED
COURSE OF ACTION
1. Check for 115 vac at the gas
solenoid leads #7 to #32A. If the
correct voltage is present but
the solenoid does not activate,
replace solenoid. See wiring dia-
gram .
2. If voltage is not present at leads
#7 to #32A, remove main supply
power to machine. Test leads #7
and #32A for continuity (zero
ohms) to the control board.
3. Control board may be faulty.
Replace.
RECOMMENDED
COURSE OF ACTION
1. Check for correct open circuit
voltage (OCV) at machine's out-
put terminals, 10 vdc to 28 vdc,
depending on arc voltage con-
trol setting. If correct OCV is
present check gun and work
cable.
2. If OCV is low, check output
capacitor and output diodes.
3. Check arc voltage control poten-
tiometer and associated wires
#205, #206 and #207 for loose
or broken connections. See
wiring diagram.
4. Control board may be faulty.
Replace.