Tweco 15C Drag-Gun LT - Manual (Page 24)

SERVICE 5-2 Manual 0-4965
Drag-gun™ lt
5.02 Basic Troubleshooting Guide
WARNING
There are extremely dangerous voltage and power levels present inside this unit. Do not attempt to
diagnose or repair unless you have had training in power electronics measurement and troubleshooting
techniques.
Basic Troubleshooting, Overview
This guide covers basic troubleshooting. It is helpful for solving many of the common problems that
can arise with this system. If major complex subassemblies are faulty, the unit must be returned to an
authorized service center for repair.
Follow all instructions as listed and complete each section in the order presented.
Common Symptoms
Problem - Symptom Possible Cause Recommended Action
Power Switch is on
but the A/C Indicator
does not light
1. Improper electrical connection.
2. System was overloaded.
3. Switch may be faulty
1. Check input power source and circuit breaker
or fuse. Check input cable and connections.
2. Turn Primary Power Switch Off and then On again.
3. Return to authorized service center for repair or replacement
Primary power switch
is on, but the cooling
fan does not work.
1. No power or incorrect power to fan.
2. Faulty fan.
1. Check electrical connections to fan.
2. Return to authorized service center for repair or replacement
No air flow at torch
when torch switch is
activated.
1. Internal connection is loose or
disconnected.
2. Internal air supply / compressor not
working.
3. Control PCB faulty
1. Check all air line connections and fittings.
2. Return to an authorized service center for repair.
3. Return to an authorized service center for repair.
Torch will not pilot
when torch switch is
activated.
1. Air pressure too high or too low.
2. Torch consumables missing.
3. Worn or faulty torch parts
4. Thermal Switch activated
1. There is no adjustment, return to an authorized service center
for repair.
2. Turn off power supply. Remove shield cup. Install missing
parts.
3. Inspect torch consumable parts. *Replace if necessary.
4. Allow the cooling fan to run for 2 minutes or longer until it
will resume operation.
Cut performance is
diminished.
1. Worn torch parts.
2. Poor Work Lead connection.
3. Current sensor or PWM PCB faulty.
1. Check current setting. *Check the Electrode and Tip for
excess wear.
2. *Check the connection of the Work Lead to the work piece.
3. Return to an authorized service center for repair or
replacement.
* See following illustrations for parts wear and work lead connection