Tweco 38 CutMaster - Manual (Page 39)

Manual 0-2888 5-11 SERVICE
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 (AC indicator flashing; TEMP indicator ON)
a. Check and clear blades.
3. Air flow obstructed (AC indicator flashing; 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 65 psi / 4.5 bar; adjust as needed.
5. Torch consumables worn
a. Check torch shield cup, tip, starter element, and electrode; replace as needed.
6. Faulty components in unit
a. Return for repair or have qualified technician repair per Service Manual.
N. No gas flow; AC indicator ON; Fan operates
1. Gas not connected or pressure too low
a. Check gas connections. Adjust gas pressure to proper setting.
2. Shield Cup not properly installed.
a. Check to see that Shield Cup is properly installed.
3. Faulty components in unit
a. Return for repair or have qualified technician repair.
O. Torch cuts but not adequately
1. Current (A) control set too low
a. Increase current setting.
2. Torch is being moved too fast across workpiece
a. Reduce cutting speed.
3. Excessive oil or moisture in torch
a. 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 contaminants in the gas, additional filtering may be needed.