6-5. Troubleshooting Power Source

Is input power connected to correct line voltage?

Yes

Is Power switch in the On position?

Yes

No

No

Connect unit to proper input voltage. (see Section 4-7).

Place Power switch in the On position. (see Section

5-1).

Is compressor

No

operating?

 

Yes

Does pilot arc

No

ignite?

 

Yes

*

Press torch trigger and listen for compressor operation. Check for Postflow air at torch. Check

Control board PC1, compressor filter, and compressor connections to PC1 and torch.

Press torch trigger and check if pilot arc ignites. Check torch consumables. *Check torch connections, relay CR1, compressor, and torch.

Is the cooling fan running?

Yes

No

*

Check Power switch S1, relay CR2, and thermistor

R1.

Does pilot arc

transfer to workpiece?

Yes

Place torch near workpiece and check if pilot arc “jumps” No or transfers to workpiece.

Check work clamp connec- tion. *Check Control board PC1 and connections, and torch and its connections.

Is Power light On?

Yes

Is Trouble light On?

No

No

Yes

*

Reset Power switch S1 and verify line power voltage.

Check relay CR2, thermistor R1, and Control board PC1.

Check torch consumables. Reset Power switch S1. If unit is overheated, wait while fan cools down unit temperature.

Check all connections, Check main transformer T1, Check inductor L1. Return to beginning of chart.

*Servicing procedure to be performed only by authorized Service Station.

OM-2248 Page 20

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Miller Electric 125C, ICE-12C manual Troubleshooting Power Source