Tweco 400 Ultra-Cut(May 2014) User Manual
Page 194
ULTRA-CUT 100 XT/200 XT/300 XT/400 XT
A-66
APPENDIX
Manual 0-5302
INV FLT (D1, INV FLT LED, red, on the Inverter Control and Fault board)
Several things can cause Inv Flt (Inverter Fault). Inverter fault is indicated by an LED, D1 on the Inverter Control and Fault
board. Inverter Fault, when it occurs, is latched on. The latch is reset next time the inverter is enabled unless it is still active
in which case it is immediately latched again. Inverter Fault will set the codes 247-252 unless it’s in conjunction with another
fault in which case that fault code may be set.
Things that can set the inverter fault:
• The local (to the inverter) + 12V & -12V bias supplies out of tolerance. There are LEDs on the Cap/Bias board that
light indicating these bias supplies are present but don’t verify they are in tolerance. It’s not likely this would happen.
More likely that fault related to the +/-12V the supply would be missing and it’s LED not on.
• Capacitor imbalance. In a cap imbalance condition D3, red Led on the main board (lower left corner of bottom or “A”
section and upper left corner of the upper or “B” section), will latch on.
• Primary over current. This is an over current condition in main switching transformer’s primary. This will latch on
but is cleared when the inverter is enabled unless it is still active in which case it is immediately latched again.
• Inverter over temperature sets the Fault signal and LED but has its own fault signal to the CCM. See OT Flt below.
OT FLT (D14, OT FLT, Inverter Control and Fault board)
• Inverter over temperature lights LED D14 on the Inverter Control and Fault board and will latch the fault signal and it’s
LED but also has its own separate fault so that will be reported as a code in the range of 253-258 or 259-264.
PWR Present
• When power is first applied to the inverter (contactor closed) CCM checks for presence of the +12V bias on the Inverter
Control and Fault board. If not present will set codes in the range of 265-270.
IS_ID (A, B, or C)
VAC_SEL (A or B)
201
Missing AC Phase
The System Bias Supply board contains circuits to detect if one of the 3 AC input phases is missing. Along with that it can
also detect if the AC voltage is too low or too high. Three phase voltage is supplied from the input terminals through the ON/
OFF Switch / circuit breaker CB1 to the System Bias board. The System Bias can operate on any 2 of the 3 phases to supply
control power and fault detection.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
J62
1
2
3
4
5
6
7
8
9
10
11
12
13
14
J27
GND
+V
1
2
4
3
HCPL-817
U?
Missing Phase a
Missing Phase b
GND
To CPU PCB
J29-16
Missing Phase
I/O PCB
SYSTEM BIAS PCB
CB1
ON / OFF
F2
F1
J60-9,18
J60-5,14
J60-1,10
3 phase AC
Art # 12310
Normally when the phase is not missing the transistor is on which turns on the opto-isolator making the signal “Missing
Phase” low.
Causes for 201, missing phase code. Codes are displayed two different ways, with an “L” meaning “Latched” or “Last”, before
the number meaning it was a problem but isn’t right now or with an “E” meaning the problem exists now.
L201 :
Most likely cause is an intermittent problem with the incoming power or possibly a loose connection on the power cord at
the back or the Ultra-Cut or Auto-Cut plasma supply.