Troubleshooting for low gas pressure faults

When the Gas Pressure fault Light Emitting Diode (LED) and the System Fault LED both illuminate while the system is ON, the gas pressure is less than the minimum pressure for the selected process, operating mode, torch, lead length, and Hypertherm® cartridge type.

Fault codes and fault LEDs

Fault code Fault LEDs Torch LED Description Stops the system from operating?
None The image shows the Gas Pressure fault Light Emitting Diode.

ON

The image shows the System Fault Light Emitting Diode.

ON

 The image shows the torch Light Emitting Diode illuminated yellow.

Flashes yellow

 The gas pressure is too low. No

Corrective action – gas supply checks

  1. Examine all the input gas supply connections, and make sure that there are no leaks or loose connections.
  2. Make sure that the internal diameter of the incoming gas supply hose is ≥ 9.5 mm (3/8 inch).
  3. Make sure that the gas inlet fitting at the rear of the plasma power supply is connected correctly and is fully tightened.
    • CSA models: Tighten the 1/4 NPT fitting to 11.3 N m (100 lbf in).
    • CE/CCC models: Tighten the G-1/4 BSPP adapter to 10.2 N m (90 lbf in).
  4. Manually adjust the gas pressure on the plasma power supply, and do a quick restart.
  5. Examine the air filter at the rear of the plasma power supply:
    1. Replace the air filter element if it is contaminated.
    2. Clean the air filter bowl, or replace it if it has damage.
  6. Start a gas test, and let the gas flow for 3 – 5 minutes to find if the gas pressure remains stable.

    Refer to Do a gas test.

  7. If the actual pressure is different from the set pressure by more than 0.2 bar (3 psi) during the gas test, continue with the next procedure.

Corrective action – more external checks

  1. Set the power switch to OFF (O), and disconnect the power cord from the power source.
  2. Examine the Hypertherm cartridge for wear and damage, and replace it if necessary.
  3. Make sure that the torch lead is not kinked or twisted, and replace it if necessary.
  4. Make sure that the torch lead has a good connection to the plasma power supply.
  5. Examine the torch lead connector and the quick-disconnect receptacle for possible damage to the pins or wires, and replace them if necessary.
  6. Optional:: If other devices use the same gas supply, make sure that those devices do not prevent sufficient gas pressure to the plasma power supply.
  7. Optional:: Clean or repair external filters, if necessary.
  8. Optional:: If the plasma power supply is connected to an air compressor, make sure that the compressor is the correct size for this system.
  9. To find if electrical interference is preventing the solenoid valve from operating correctly, move the plasma power supply to another location.
  10. If you continue to get the low gas pressure fault, continue with the next procedure.

Corrective action – internal checks

  1. Set the power switch to OFF (O), and disconnect the power cord from the power source.
  2. Remove the plasma power supply handle and cover.
  3. From the fan side of the plasma power supply, make sure that there are no leaks or loose connections at the connection points on the gas supply line.
  4. Examine the two gas hoses that connect to the solenoid valve, and replace them if they have kinks or other damage.
  5. Examine the rear of the quick-disconnect receptacle, and replace the receptacle if necessary.
    • Is the receptacle fully tightened in the front panel?
    • Are the receptacle wires pinched or twisted, or do they have other damage?
  6. Make sure that the solenoid valve wire connections are not loose.

Verification

  1. After you have completed all of these troubleshooting steps, do a cold restart.
  2. Fire the torch.
  3. If the Gas Pressure fault LED and System Fault LED continue to illuminate, replace the solenoid valve.