Tweco 400 Ultra-Cut(May 2014) - Manual (Page 211)

ULTRA-CUT 100 XT/200 XT/300 XT/400 XT
Manual 0-5302 APPENDIX A-83
valve. If the pump is operating some coolant may be exiting that fitting as well. If these fittings are below the coolant level
you may have to drain out some of the coolant to see this. If a strong stream is exiting the bypass (lower) fitting but nothing
from the upper fitting, you probably have some kind of blockage.
Reasons for 404 faults (Coolant not flowing):
• In new installation, coolant has not circulated all the way through the leads. Add more coolant if necessary and recycle
the power to restart the pump and 4 minute timer.
• Coolant supply & return leads are reversed, check valve in torch coolant return prevents reverse flow.
• Torch parts removed or are wrong style so torch check valve shuts off flow.
• Torch coolant tube damaged or the tube extension (if required) missing.
• No power to pump motor.
• Pump/motor failure.
• Bypass valve defective or adjusted incorrectly.
Damaged Coolant Tube
Coolant tube includes a check valve at its upper end. When cartridge with consumables is not installed the spring loaded
coolant tube is fully extended closing the check valve preventing coolant from leaking out.
When consumables are in place they push the tube inward, opening the check valve, allowing coolant to flow. The coolant
tube has fingers on the end to contact the inside of the electrode and allow coolant to flow through the openings between
the fingers.
The fingers can be bent over or broken if reasonable care is not taken when the cartridge is not in place. If the fingers are
bent or broken it shortens the tube so the consumables may not push the tube in enough to open the check valve resulting
in no coolant flow. The coolant tube assembly may be replaced separately from the torch head.
Some consumables use an extension on the coolant tube. A missing extension will not allow the check valve to open.
Art # 12312
Coolant Tube Extension
Fingers
Internal Check Valve
No Power to the Pump Motor
The pump motor is powered by 230 VAC controlled by the MC3 control relay. During the 4 minutes after turning on power,
before the 404 fault code is displayed, measure for 230 VAC at the motor connector J16 pin 1 to pin 3.
a. If the pump motor is not getting 230 VAC, measure for 24 VAC on the coil of MC3. If present and the relay contacts aren’t
closed the relay is defective. Note, the coil is rectified so you won’t measure continuity of even a good coil.
b. If 24 VAC is not on the MC3 coil check for D27 on the relay board being ON. If it’s on the Relay board should be providing
the 24 VAC so if it’s not the Relay board may be defective. Measure for 24 VAC at J9-6 to J9-12 on the Relay board. If
24 VAC is present and D27 is on, the Relay board or the wire harness is defective.
c. If D27 is not on, measure on the CCM I/O board between TP3 and the common at TP1. It should be low, near zero volts.
If not the CCM is probably defective. Jumper TP3 (I/O board) to TP1. If the pump comes on now replace the CCM.
d. If jumping TP3 to TP1 does not turn the fans on then the Relay board or the 40 pin ribbon cable pin 13 is at fault.