Tru-Weld SC2400 Arc Welder - Manual (Page 25)

25
SC2400 Troubleshooting
Problem Possible Cause Fix
Unit will not turn on. No power. 1. Test 3 phase power to control contactor.
2. Check taps (if applicable) on main transformer.
3. Check voltage selection plug near control transformer.
4. Check fuse located on control transformer.
5. Look for power available LED on control transformer.
6. Make these checks before contacting a TWE Rep.
Fan does not run when unit is
turned on. This is normal. The fan will cycle on when the main bridge has reached
nominal operating temperature. Ambient temperature of the
weld site should also be taken in consideration.
Fan runs continuously (does
not cycle on/off) Thermostat circuit A fault in the thermostatic circuit will cause the fan to run
continuously. Call your TWE Rep for repairs.
Unit turns on, coil boot test is
good, no trigger from weld
gun. Bad connection or
faulty equipment. 1. Test control cable by plugging weld tool directly into unit
(4 conductor straight through wiring).
2. Check gun trigger resistance (<100 ohms when closed).
3. Check to see if trigger LED on control panel responds.
4. Check to see if weld tool is wired according to one of the
three diagrams in Chart A (see page 25).
5. Locate Touch/Trigger Control Board #16002 (Chart B).
Check and note the operation of the driver LED’s and
report the status.
Unit turns on, no coil test, no
lift from gun coil, trigger is
good. Bad connection or
faulty equipment. 1. Test control cable by plugging weld tool directly into unit
(4 conductor straight through wiring).
2. Check 10 amp fuse on control board box next to break‐
ers.
3. Check hand tool coil resistance (12 ‐ 40 ohms).
4. Locate Touch/Trigger Control Board #16001 (Chart B).
Check and note the operation of the driver LED’s and
report the status.
Gun lifts, no weld arc drawn. Bad connection or
faulty equipment. 1. Check connections for ground and weld tool leads.
2. Check if contact LED on control panel lights when stud is
touched to work surface (closing circuit).
3. Check the two circuit breakers on the control board box.
4. Check to see if you have the sustaining arc (a small blue
arc for the duration of the weld time).
5. Check to see if the stud sparks at the end of the weld
cycle (hot plunge).
6. Locate Touch/Trigger Control Board #16001 (Chart B).
Check and note the operation of the driver LED’s and
report the status.