Tweco 200 XT Auto-Cut 400V - Manual (Page 136)

AUTO-CUT 200 XT
A-54 APPENDIX Manual 0-5284
Relay Board or CCM
If D11 on the Relay PCB is still on after the previous tests, measure the output to the CCM on the 40 pin ribbon
cable (Relay J4 to CCM J23) between pins 23 (-) and 25 (+). It should be less than 0.1V. If not, the Relay board
is bad. If voltage is zero then the CCM is defective.
2. 208 code comes on during preflow:
IM#1 and the Pilot board are enabled near the end of preflow. To have unwanted current there must be a path
(short) for current to flow between the inverter negative output (negative cable/torch electrode) and the Pilot
return/tip before the arc starter is enabled for pilot ignition.
Possible causes are:
• Short between electrode and tip due to mismatch of consumables, damaged consumables or foreign mat-
ter between tip and electrode. An electrode at the end of its life may lose material that can short between
electrode and tip.
• Defective or incorrectly installed user supplied equipment such as torch height controls that make con-
nections to power supply output.
• Short between power supply negative output cable and pilot cable.
• Shorted torch body.
Troubleshooting:
1. Remove and insulate (may have voltage on it) the pilot cable from the rear of the unit. Attempt to pilot. If
no 208 code shows, it confirms problem is outside the power supply.
2. Remove and check consumable for damage, cleanliness and missing (gas dist, etc.) or wrong components.
3. Disconnect user supplied equipment and see if fault still exists.
4. Inspect Arc Starter for broken/disconnected wires or burnt components.
5. Inspect inside the torch mounting tube for shorts.
6. If all else fails disconnect the pilot wire from the back of the torch head. Insulate it well or keep it away from
any metal, it may have HF (high frequency) on it when you try to start. Try to start, if the 208 is gone now
the torch head is shorted.
209 Not used. Reserved codes from the earlier product.
210–211 Output current, measured by the work lead current sensor, is too high (210) or too low (211).
These are warnings and do not shut down the process but may explain poor cut quality or poor parts life.
Individual inverter sections have their own current sensors and the work lead has a current sensor whose
signal should equal the sum of the individual inverter sections. Each section is set to output a certain current
based on its ”demand” signal. If the current differs from the total “demand”, sum of the individual demands,
the individual sections are checked to determine if their output is correct compared with their demand signals.
If the individual sections are correct but the work current sensor signal differs from the total demand by more
than 16% code 210 (too high) or 211 (too low) is displayed.
If an individual inverter section was found to be in error causing the total current to be wrong, a different code
would be displayed in the range of 212 to 223 depending on which section was at fault.
Possible causes for work current signal too high:
• HCT1 Work Current Sensor
• Relay PCB
• CCM