Troubleshooting Principle - Matco Tools MA48 Operator's Manual

5.2 Trouble Shooting Principle
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.
A. The cutting torch fails to ignite the arc when torch trigger depressed, DC pilot light on.
1. Gas pressure too high, gas test then adjust gas pressure 60 psi (to 4.2 bar).
B. The cutting torch fails to ignite the arc, when torch trigger depressed, torch/air pilot light flashes.
1. The shield cup improper installation, turn off the power source, install and screw it down properly, then turn
on the power source.
C. The cutting torch fails to ignite the arc, when torch trigger depressed, DC pilot light ON and air
flows intermittently.
1.The electrode or nozzle improper installation, turn off the power source, install the electrode or nozzle, and
screw shield cup down properly, then turn on the power source.
D .The cutting torch fail to ignite the arc, when torch trigger depressed, DC pilot light ON and air
flows intermittently.
1. Short-circuit for burned-out and other abnormal situation, turn off the power source to change the
electrode and nozzle.
E. Power lamp and temperature lamp ON.
1. Air flow blocked, check for blocked air flow around the unit and correct condition.
2. Fan blocked, check and correct condition.
3. Unit is overheated, let unit cool down for at least 5 minutes. Make sure the unit has not been operated
beyond Duty Cycle limit, refer to technology parameters in Section 2.
4. Faulty components in unit, return for repair or have qualified technician repair per Service Manual.
F. Torch fails to ignite the arc when torch switch is activated
1. System is in SET mode. Change to RUN mode.
2. Faulty torch parts, inspect torch parts and replace if necessary.
3. Gas pressure too high or too low, adjust to proper pressure.
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