Troubleshooting for phase errors in choppers

Diagnostic codes 752, 753, 754

Diagnostic codes 752 – 754 occur when there is a 3-phase error in a chopper.

Symptoms

Code Symptoms XPR® models XPR action Code cancels with...
752 There is a 3-phase error in Chopper 1. All models Shut down Remote on-off
753 There is a 3-phase error in Chopper 2. XPR300®, XPR460®
754 There is a 3-phase error in Chopper 3. XPR460

Corrective action

  1. Make sure that the input-line voltage is ±14% of nominal.

    Refer to General input power requirements.

  2. Remove the power from the cutting system.
  3. Remove the cover from the contactor.
  4. Examine the contacts for excess wear, and replace the contactor if necessary.
  5. Examine the following contactor components for loose connections:
    • Contactor
    • Input to chopper
    • Power cord
  6. Examine the phase conductors to the choppers for loose connections.
  7. Tighten loose connections if found.
  8. If you cannot find or correct the problem, speak to your cutting machine supplier or regional Hypertherm® Technical Service team.