Tweco 400 Ultra-Cut XT Plasma Cutting System - Manual (Page 216)

ULTRA-CUT 100 XT/200 XT/300 XT/400 XT
A-82 APPENDIX Manual 0-5297
Possible causes:
• Ambient is too high.
• Cooling fan(s) not operating.
• Disrupted air flow.
• TS2, Ambient temperature sensor, shorted (very unlikely) or otherwise defective.
• Defective Relay board.
• Defective CCM.
• Defective Relay board.
Troubleshooting:
1. If room temperature exceeds 40 deg C, cool the room, or operate the unit at reduced duty cycle or lower
current.
2. Confirm that air is exhausting from opening in the right side panel. As the fan(s) are behind the radiator
it’s hard to see them to confirm they are turning but perhaps you can use an inspection mirror. Be careful
not to get the mirror or your hands into the blades. 100 & 200A units have 2 smaller fans, 300 & 400A have
one larger one.
3. It is unlikely these high ambient temperature codes would be set before some other temperature related code
but just in case we’ll note that leaving the side panels and cover off, especially the left lower side or the top
cover will reduce the air flow. Also the radiator fins clogged with dust will reduce air.
4. To test TS2 remove J2 from the Relay board and measure the resistance between pins 4 & 6 of the J2 harness
connector. The resistance varies from about 33K ohms at 0 degrees C to about 12K ohms at 20C to 5.3K ohms
at 40C.
5. If TS2 is within the correct range the problem may be with the Relay board or the CCM.
a. The output from the relay board going to the CCM is on pin 30 of the 40 pin ribbon cable (J4 of Relay
board to J23 of the CCM I/O board). It is an analog voltage that should range between 0.44V at 0 deg
C to 1.6V at 40C. If it is confirmed that the room ambient is not above 40C and Ambient temperature
signal at pin 30 is higher than 1.6V then the Relay board is defective.
b. If Ambient temperature signal at pin 30 is OK, less than 1.6V, and the room ambient is not above 40C
then the CCM is bad.
265-270 Inverter No Input Power
There are several digital signals on the ribbon cables between the inverter sections and the CCM that involve
some level of voltage. These include AC_INPUT_FLT\, INVERTER _FLT\, OVERTEMP_FLT\ and POWER_
PRESENT. Normally all of these should be high. Before power is applied to the inverter modules the CCM
has already performed a continuity check to see if that section is in place and it’s ribbon cable connected (code
224 & 237). As soon as power is applied to the inverter modules the CCM checks these 4 signals and, having
already confirmed there is an inverter whose ribbon cable is connected. If it finds none of the signals have volt-
age, it assumes there is no power into the section or something is wrong with that inverter section’s bias power.
Possible causes:
• The 3 input phases, J103-105 to that inverter section not connected.
• The circuit breaker CB2 providing the 120 VAC to the contactor (and Remote Arc Starter) has tripped.
• The contactor powering that section (and others) defective.
• Relay board defective.
• Inverter defective.
• CCM defective.