Thermal Dynamics Ultra-Cut 300 XT, Operating Instructions Manual

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ULTRA-CUT 400 XT
Manual 0-5275 APPENDIX A-85
b. If D35 is off remove J85 from the Relay Board and measure for minus 12-15 VDC on pin 3 of J85 PCB
header. If not there the Relay Board is defective. If voltage is present plug J85 back in and measure pin
3 again. If the voltage is not there now there is a short in the module or the wires.
c. Assuming the voltage is OK at J85-3, measure at J85-1. This should be more negative than -5V. If it is
then the Relay Board is defective.
3. Problem inside the 1Torch Module. Refer to the Removing and opening the 1Torch module near the begin-
ning of this section for directions to open the module.
a. Find the W5 contactor. With power applied and the system at idle, measure from W5’s main terminal
T2, 3 or 4. With meter negative lead on TP1 of either the XT Relay Board or the CCM boards. Should
measure more than -5VDC negative, normally -12 to -15VDC. If the voltage isn’t there measure for it on
K201-5. If not there then perhaps the wire harness between J85 and J86 is bad or wire from J86 to K201.
b. Confirm that K201 is not energized by measuring across its coil, pin 7 to pin 8. Should be zero but if it’s
24 VDC then the Relay Board is defective.
c. If voltage was OK at K201-5, measure from TP1 to K201-1. If not there K201’s NC contact is open or the
diode D201 is open. D202 in the wire 223/223D under shrink tubing.
703 Detection circuit fault.
1. When the 1Torch trigger is pressed, circuits check for the consumable parts being in place (explained under
702 code). With the consumables in place and K201not energized, the signal “/Pressure OK 1Torch” on the
Relay Board will be low. As soon as K201 is energized, the tip with the -15VDC is no longer connected to
J85-1 so D35 goes out. Since the gas solenoid SOL4 has not been turned on yet, the signal “/Pressure OK
1Torch” should go high. This checks that K201 is functioning and the pressure switch PS2 is normally open.
If either of these is not correct you get the 703 fault. All this happens very quickly so it is nearly impossible
to measure with a meter and will need to use a process of elimination.
a. Remove the 3 pin connector J85 from the Relay Board. Press the 1Torch trigger. You should get the 702
fault. If instead you get 703 the PS2 is shorted closed. This is an unlikely failure.
b. If you still get 703 with J85 removed, you will need to determine if the Relay Board is trying to turn on
K201 or if the board is defective. Reconnect J85. In response to the fault even if the Relay board turns
K201 on it will immediately turn it off again. Your meter should detect a momentary voltage pulse or
just flicker if the voltage is being applied properly.
i. Measure between TP1 (common) on the Relay board and J11-9. Each time you trigger the torch the
meter should flicker. If it does you will need to open the 1Torch Module to investigate problems
there. Refer to the Removing and opening the 1Torch module near the beginning of this section for
directions to open the module. If there is no sign of voltage at J11-9 the Relay Board may be faulty
but first we need to check that K201 coil or D202 isn’t shorted.
ii. Remove power. Remove J11 from the Relay Board. On the J11 harness connector measure for resis-
tance of 400-800 ohms between pins 8 & 9. Do not use the meters diode scale. If resistance is less
than 400 ohms reverse your leads, you may be measuring the diode D202. If you measure a short,
much lower than 400 ohms, that may be the cause of not seeing any movement of the meter.
iii. A short or an open will require opening the 1Torch Module to determine the cause. Refer to the
Removing and opening the 1Torch module near the beginning of this section for directions to open
the module. In the case of a short determine if the D202 is bad or if the relay coil is shorted or open.
K201 is the relay toward the front of the module; K200 is the one to the rear.