Tweco PAK 200i - Manual (Page 151)

PAK 200i
Manual 0-5335 APPENDIX A-71
3. Check for 230 VAC at either of the fan connectors, J72 & J73. It may also be measured at the rear panel con-
nector J70 for the HE400XT fan.
a. If the fans are not getting 230 VAC, measure for 24 VAC on the coil of MC2. 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 MC2 coil check for D24 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 must be defective.
c. If D24 is not on, measure on the CCM I/O board between TP2 and the common at TP1. It should be low,
near zero volts. If not the CCM is probably defective. Jumper TP2 (I/O board) to TP1. If the fans now
come on replace the CCM.
d. If jumping TP2 to TP1 does not turn the fans on then the Relay board or the 40 pin ribbon cable pin 19
is at fault.
404 Coolant System Not Ready
When power is applied to the system with External Plasma Enable satisfied and Plasma Power Supply Enabled
(switch on �010 or TSC 3000), assuming there is enough coolant in the tank, after some initial tests taking about
15-20 seconds (see manual section 4 for details of the Start-Up Sequence) the pump will start. Coolant will be
pumped through the system. Flow is measured by the FS1 flow switch placed in the torch coolant return path
just before the radiator (see plumbing diagram). If the flow doesn’t reach at least 0.75 GPM (2.8 lpm) or 0.5 GPM
(1.9 l/m) for PAK 200i within 4 minutes it will set the 404 fault. The reason for the 4 minutes is a new dry system
especially one with long torch leads will take some time before the leads, hoses, radiator and cold plates are full
of coolant. More coolant may have to be added. On a system that has been run before it normally takes only a
few seconds to establish proper flow. In any case the pump will run for 4 minutes before setting the 404 fault.
First determine if the pump motor is running and if so is there any coolant flowing. With the right lower side
panel removed touch the pump and feel for vibration to indicate if the motor is running. Observe the clear
coolant hoses to see if they are full of coolant. There are two hose fittings on the back of the tank. The upper
one is the coolant return. Remove the tank filler cover. You should see a fairly strong stream of coolant from
that fitting. The lower fitting is from the pump bypass 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 neces-
sary and recycle the power to restart the pump and 4 minute timer.
• No power to pump motor.
• Pump/motor failure.
• Bypass valve defective or adjusted incorrectly.
For automation XT torches only:
• 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.
Damaged Coolant Tube (XT torches only)
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.