Tweco 400 XT Ultra-Cut Plasma Cutting System - Manual (Page 167)

ULTRA-CUT 400 XT
Manual 0-5275 APPENDIX A-59
Troubleshooting:
1. If it reports the current of an individual inverter section is too high, the problem is the inverter.
2. If the report is current too low (which included no current) check the connections.
3. The ribbon cable for the first inverter section (IM#1A) must connect to that section only but if there are 2 additional sec-
tions, unit is 200A or greater, swap the ribbon cable going into those sections.
a. If it now reports a different section as bad, the one whose cable was moved, then the original section was bad.
b. If it still reports the original section the ribbon cable or the CCM is bad (unlikely).
c. Swap both ends of the ribbon cable with one next to it. If still reports the original section then the problem is with
the CCM if not then it’s the ribbon cable.
�. If it’s the first inverter section or it’s a 100A unit so there’s no other inverter to swap cables with, replace the inverter.
Additional hint: Inverter control PCBs have a green LED, D2�, PWM ON, that lights when that section is enabled and has a
demand signal. The LED brightness is relative to the output so may be very dim if output is low. If that LED doesn’t light
may indicate a defective inverter (control board).
224 Inverter 1 not found.
There must be an inverter connected in the 1st section, 1A, to be able to pilot. During the power up sequence, before power
is connected to the inverters, the CCM does a continuity test to see if its section 1A ribbon cable (J31 on CCM) is connected.
Causes & troubleshooting:
• As this is just a continuity test it is very unlikely to be a bad inverter. Most likely a poor connection or defective ribbon
cable.
o Check ribbon cable connections at both ends of INV1A to CCM J31 (1A) cable. Make sure it is plugged into J31,
the top connector, on the CCM.
o Plug a different inverter cable into J31, doesn’t matter which one for this test as long as it’s plugged into an inverter
on the other end. If still gives 22�, “Inverter 1 not found” fault, it’s a bad CCM. Otherwise it’s the ribbon cable.
225-230 Inverter Revision and CCM incompatible.
If sometime in the future we should make a change to the inverter making it incompatible with older CCM we have included
a hardware key that would change to indicate this. During the power up sequence, before power is connected to the invert-
ers, the CCM does a continuity test to determine what is the hardware key configuration. The key uses 3 lines of the CCM to
inverter ribbon cable which are named IS_ID_A, IS_ID_B, IS_ID_C (on pins 12, 13 & 1�) and checks for continuity to a �th
line OUTCOM (pin 9). The test consists of applying voltage to OUTCOM and looking for that voltage coming back on the 3
ID pins. The present configuration has all 3 lines connected to OUTCOM so all 3 should be high.
To get the 225-230 code now when we don’t have any incompatible revisions would most likely be a bad connection in the
ribbon cable between the CCM and the inverter or a defective CCM (unlikely).
• On the inverter section swap the ribbon cable with that of a different inverter section. If fault remains unchanged, still
calls out the original inverter section, the problem is with either ribbon cable or CCM.
• On the inverter end put the ribbon cables back in their original positions. Now swap suspect ribbon cable with another
one on the CCM. If the fault now moves to a different section it’s the ribbon cable. If it remains with the original sec-
tion the problem is the CCM.