Tweco 300 XT Ultra-Cut Plasma Cutting System - Manual (Page 172)

ULTRA-CUT 300 XT
�66 PPENDIX Manual 0�5�7�
Troubleshooting:
1. If room temperature exceeds �0 deg C, cool the room, or operate the unit at reduced duty cycle or lower
current.
�. Confirm that air is exhausting from opening in the right side panel. s 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 & �00 units have � smaller fans, 300 & �00 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. lso the radiator fins clogged with dust will reduce air.
�. To test TS� remove J� from the Relay board and measure the resistance between pins � & 6 of the J� harness
connector. The resistance varies from about 33K ohms at 0 degrees C to about 1�K ohms at �0C to 5.3K ohms
at �0C.
5. If TS� 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 �0 pin ribbon cable (J� of Relay
board to J�3 of the CCM I/O board). It is an analog voltage that should range between 0.��V at 0 deg
C to 1.6V at �0C. If it is confirmed that the room ambient is not above �0C and mbient temperature
signal at pin 30 is higher than 1.6V then the Relay board is defective.
b. If mbient temperature signal at pin 30 is OK, less than 1.6V, and the room ambient is not above �0C
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 C_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
��� & �37). s soon as power is applied to the inverter modules the CCM checks these � 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.
Troubleshooting:
1. Check that the input power cables are connected to the inverters.
�. Check if the contactor for that section (W1 for 1, 1B, �; W� for �B, 3, 3B) is energized.
a. There is a rectangular section in the middle of each contactor top that can be used to attach auxiliary con�
tacts. This can also be an indicator of contactor operation as it pulls in when the contactor is energized.
b. Check for CB� on the rear panel being tripped. The white button marked “5” indicating it’s 5 amps, will
pop out if tripped. Reset it and if it pops out again something (contactor coil?) may be shorted.
c. Measure for 1�0 VC on the contactor coil. If present, but the contactor isn’t pulled in, it’s probably a
defective contactor.