Troubleshooting for low fan speeds – MAGFAN

Diagnostic codes 744 – 746

Diagnostic codes 744 – 746 occur when a magnetics fan is under performing.

Symptoms

Code Symptoms XPR® models XPR action Code cancels with...
744 The fan tachometer feedback for MAGFAN 1 is less than the minimum acceptable value. All models None
  • Set process
  • Remote on-off
745

The fan tachometer feedback for MAGFAN 2 is less than the minimum acceptable value.

For the XPR170®, code 745 starts the End of Cycle State because the system has a smaller number of thermistors and different magnetics behind MAGFAN 2.

 All models End of cycle
746 The fan tachometer feedback for MAGFAN 3 is less than the minimum acceptable value. XPR460® None

Corrective action for code 744

  1. Use the Fan diagnostic codes diagram to identify the location of the MAGFAN in the plasma power supply.
  2. Make sure that the following fan connections are good, and tighten loose connections if found:
    • The fan connector
    • The wiring to J2 and J5 on the fan power distribution Printed Circuit Board (PCB)
    • The wiring to J7 on the control PCB
  3. Examine the 48 VDC power source output.
  4. If the power output is not correct, replace the 48 VDC power source.
  5. Examine the solid-state relay, and make sure that it is operating correctly.
  6. If you do not find any loose connections and the 48 VDC power source and solid-state relay are good, replace the fan.

Corrective action for code 745

  1. Use the remote on-off switch to set the power to OFF.
  2. Use the remote on-off switch to set the power back to ON.
  3. Send a process ID to the plasma cutting system, and select the Start command to fire the torch.
  4. Use the Fan diagnostic codes diagram to identify the location of the MAGFAN in the plasma power supply.
  5. Make sure that the fan motor is ON, and examine the fan:
    If you see this condition...Do these steps...
    The fan blades are turning while the fan motor is ON. The fan tachometer is bad. Replace the fan.
    The fan blades are not turning while the fan motor is ON. Make sure that the following fan connections are good, and tighten loose connections if found:
    • The fan connector
    • The wiring to J2 and J5 on the fan power distribution PCB
    • The wiring to J7 on the control PCB

    If MAGFAN 2 is defective, you can temporarily interchange that fan with MAGFAN 1. Do not operate the plasma cutting system without a magnetics fan that is operating correctly.

  6. Examine the 48 VDC power source output.
  7. If the power output is not correct, replace the 48 VDC power source.
  8. If you do not find any loose connections and the 48 VDC power source and solid state relay are good, replace the fan.