Tweco PC250 - Manual (Page 20)

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C. AC indicator ON, Over TEMP (temperature) indicator not lighted, no gas flow in purge or pre-flow.
1. Gas not connected or pressure too low.
a. Check source for at least 50 psi (3.5 BAR) during purge or pre-flow, adjust gas pressure to 50 psi.
2. Air filter or air line blocked, torch leads blocked.
a. Replace filter cartridge. Check that air lines and torch leads are free of twists and kinks.
D. AC indicator ON, Over TEMP (temperature) indicator not lighted, no gas flow when torch switch
pressed.
1. Shield cup not properly installed on torch.
a. Check that shield cup is fully seated against torch head.
2. Faulty Torch Switch or PIP Assembly in torch holder.
a. Refer to Servicing Torch Head Components.
3. Faulty Main PC Board
a. Repair/Replace Power Supply
E. AC indicator ON, Over TEMP (temperature) indicator not lighted, gas flows. Torch does not pilot.
1. Faulty torch parts
a. Inspect torch parts and replace if necessary.
2. Gas pressure too high.
a. Set pressure to 50 psi (3.5 BAR).
3. Faulty main PC board.
a. Repair/replace power supply.
F. Torch pilots but does not cut.
1. Work lead not connected.
a. Make sure work lead is connected securely to bare metal.
2. AC input power too low
a. Use shortest service to breaker panel possible. Refer to specifications for PC250 for input power cable
requirements.
3. Faulty Main PC Board
a. Repair/Replace Power Supply