Tweco 400 XT Ultra-Cut Plasma Cutting System With Automated Gas Control - Manual (Page 185)

ULTRA-CUT 400 XT
Manual 0-5306 APPENDIX A-61
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 & 14) and checks for continuity to a 4th
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.
231-236 Inverter VAC Mismatch.
Different inverter modules are manufactured for 480VAC, 380-415VAC & 208-230VAC operation voltages. There is a key,
called inverter ID, read through the inverter’s ribbon cable, to identify which voltage range the inverter is designed for. The
unit itself is wired differently for the different input voltages and part of that includes a jumper at J61 on the System Bias
board that indicates to the System Bias board what voltage the unit is wired to accept.
At power on, the System Bias board measures the incoming voltage, determines what input voltage range it fall into and
sends that range information to the CCM. Before Appling power to the inverters by turning on the input contactors, the CCM
checks that each connected inverter is of the correct voltage matching that of the System Bias board. The inverter ID’s are
read from the lowest section to the highest so in all cases if it truly is a wrong voltage inverter it should call out the A section
whose code is read first. A VAC mismatch of a B section is likely another problem.
Possible causes:
• Wrong voltage inverter (very unlikely but easy to check).
• System Bias board wrong J61 jumper (unlikely but easy to check)
• Defective inverter.
• Ribbon Cable
• CCM
• System Bias board defective.
Troubleshooting:
1. If System Bias board has either the wrong jumper or is defective it will call out the first inverter section, code 231, because
all the inverters won’t match the incorrect signal and 1A is checked first.
a. For the jumper Wire #48 should be connected from J61-1 to:
i. J61-2 for 208-230 VAC
ii. J61-3 for 400 VAC
iii. J61-4 for 480 VAC
Check for proper connection and continuity.
b. System Bias may be defective reporting the wrong voltage ID. On the output of the System Bias board at J62 measure
relative to TP1 or ( J62-8, 24VDC_RET) to J62-12 for signal /VAC_IDAb and J62-14 for signal /VAC_IDBb. The 2
signals should read according to this table. “0” = 10-12V; “1” = 24V.
signal 230V 400V 480V ERR
/VAC_IDAb 0 1 0 1
/VAC_IDBb 0 0 1 1