Tweco 81 with SL100SV - Manual (Page 83)

Manual 0-4641 5-19 SERVICE
5
5.06 Pilot Arc Problems
WARNING
The following tests must be performed with the power supply connected to primary input power. There are extremely
dangerous voltage and power levels present inside this unit. Do not attempt to diagnose or repair without proper
training in power electronics measurement and troubleshooting techniques.
Locate your symptom below:
A. Torch will not pilot; gas flows; AC indicator ON, GAS , TEMP , and DC indicators OFF
1. Gas pressure is below power supply minimum requirement. (Minimum pressure for power supply operation is lower
than minimum required for torch operation.)
a. Adjust gas pressure per pressure setting label on power supply.
B. Torch will not pilot; gas flows; AC and Gas indicators ON; TEMP and DC indicators OFF
1. Gas pressure is below torch minimum requirement (Minimum pressure for power supply operation is lower than
minimum required for torch operation.)
a. Adjust gas pressure per pressure setting label on power supply.
2. Power Supply RUN / SET switch in SET position
a. Place RUN / SET switch to RUN position.
3. Upper O-ring on torch head is in wrong position.
a. Remove shield cup from torch; check position of upper O-ring. Correct if necessary.
Upper Groove
with Vent Holes
Must Remain Open
Threads
Upper O-Ring
in Correct Groove
Lower O-Ring
Art # A-03725