Lincoln Electric COMMANDER 400 SVM133-B Service Manual page 68

F-14
TROUBLESHOOTING GUIDE
PROBLEMS
(SYMPTOMS)
The welding arc is "hot", "spattery",
"cannonballs" or "flares up". The
engine runs normally. The auxil-
iary power is normal.
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 1-
800-833-9353 (WELD).
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
WELDING PROBLEMS
1. Check to make sure that the
machine settings match the
weld application.
2. If the remote control unit is not
connected to the machine,
make sure the Local/Remote
switch (S1) is in the "Local"
position.
3. If a remote control unit is con-
nected, and the machine oper-
ates normally when the switch
is in the "Local" position, the
remote control cable or unit
may be faulty.
replace.
CAUTION
COMMANDER 400
Observe Safety Guidelines
detailed in the beginning of this manual.
RECOMMENDED
COURSE OF ACTION
1. Perform the Range Switch
Test.
2. Perform the Fine Control
Potentiometer Test.
3. Check for poor connections at
the J1 molex plug at the control
board. Also, perform the Shunt
Calibration Test.
4. Check for poor connections at
J4 pins 1, 2, 3, 6, & 7 at the con-
trol board. Also, perform the
Exciter Voltage Feedback
Test.
Check or
5. Check for poor connections
along lead #207 at the negative
CC output stud, and at J6 pin
10 molex plug at the control
board. This is CC arc voltage
feedback input. Will not effect
welding in the CV tap.
6. Check for poor connections
along lead #204A at the diode
bridge and at J6 pin 4 molex
plug at the control board. This
is control board common.
7. Check for poor connection
along lead #208 at the negative
CV output stud and at J21 pin 6
molex plug at the CV daughter
board. This is CV voltage feed-
back input. Will not affect weld-
ing in the general fab or pipe
taps.
8. Check for poor connection at
J21 pins 1 & 4 at the CV daugh-
ter board. This is CVSCR gate
drive output.
welding in the general fab or
pipe taps.
9. Check the weld & CV chokes (if
so equipped) for turn to turn
shorts.
F-14
Will not affect