Tweco PC-500 - Manual (Page 41)

Manual 0-4601 5-9 SERVICE
5. Excessive oil or moisture in torch
a. Put RUN / RAPID AUTO RESTART / SET switch in SET (down) position. Hold torch 1/8 inch (3 mm) from
clean surface while purging and observe oil or moisture buildup (do not activate torch). If there are contami-
nants in the gas, additional filtering may be needed.
6. Fluctuations in input power
a. Have electrician check input line voltage.
7. Faulty components in unit
a. Return for repair or have qualified technician repair per Service Manual.
M. Arc shuts off during operation; arc will not restart when torch switch is activated.
1. Power Supply is overheated (TEMP indicator ON)
a. Let unit cool down for at least 5 minutes. Make sure the unit has not been operated beyond Duty Cycle limit.
Refer to Section 2 for duty cycle specifications.
2. Fan blades blocked (TEMP indicator ON)
a. Check and clear blades.
3. Air flow obstructed (TEMP indicator ON)
a. Check for obstructed air flow around the unit and correct condition.
4. Gas pressure too low (GAS indicator OFF when torch switch is activated)
a. Check source for at least 60 psi / 4.1 bar; adjust as needed. (Minimum pressure for power supply operation
is lower than minimum required for torch operation.)
5. Torch consumables worn
a. Check torch consumables per Torch manual; replace as needed.
6. Faulty components in unit
a. Return for repair or have qualified technician repair per Service Manual.
N. AC indicator remains ON when shield cup is removed
1. Faulty PIP switch in torch
a. Check PIP switch for continuity; replace if necessary