Tweco 400 XT Ultra-Cut Plasma Cutting System With Automated Gas Control - Manual (Page 184)

ULTRA-CUT 400 XT
A-60 APPENDIX Manual 0-5306
3. In the section on code 207 for Relay PCB it describes measuring the work current sensor signal when there is no current.
The signal should be zero and we assume it is or else you should have gotten the 207 code. If the zero current signal
is correct but there is an error while cutting, measure the signal on the 40pin ribbon cable (Relay board J4 to CCM J23)
pins 27 (-) & 28 (+). The signal voltage should equal the cutting current * 0.0266. For example for 100A (100*0.0266)
=2.66V.
• If this signal is correct the fault is the CCM
• If it’s not correct the error may be in the Relay board or sensor. Follow the instructions for code 207 to measure the
voltage to and signal from the current sensor at J1 on the Relay board. The signal voltage should equal the cutting
current * 0.0133. For example for 100A (100*0.0133) =1.33V. For 400A would be 400*0.013 3= 5.33V.
• If power and signal are correct Relay board is faulty. If not correct the HCT1 work current sensor is bad.
212-223 Incorrect output from an inverter section.
Work current high or low due to wrong output from one inverter section. Individual code indicates which section.
Causes may be:
• The named inverter section output connector, J102 A or B, is not plugged in or is damaged.
• Ribbon cable with bad connection, perhaps not fully locked in place at either the inverter or the CCM.
• Defective inverter section.
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.
4. 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, D24, 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 224, “Inverter 1 not found” fault, it’s a bad CCM. Otherwise it’s the ribbon cable.