Troubleshooting Power Source - Miller Electric Spectrum 125C Owner's Manual

6-5. Troubleshooting Power Source

Is input power
connected to
correct line
voltage?
Yes
Is Power
switch in the
On position?
Yes
Is the cooling
fan running?
Yes
Is Power light
On?
Yes
Is Trouble
light On?
No
OM-2248 Page 20
Connect unit to proper input
No
voltage. (see Section 4-7).
Place Power switch in the
No
On position. (see Section
5-1).
*
Check Power switch S1,
No
relay CR2, and thermistor
R1.
*
Reset Power switch S1 and
No
verify line power voltage.
Check relay CR2, thermistor
R1, and Control board PC1.
Check torch consumables.
Reset Power switch S1. If
Yes
unit is overheated, wait
while fan cools down unit
temperature.
No
Is compressor
operating?
Yes
No
Does pilot arc
ignite?
Yes
No
Does pilot arc
transfer to
workpiece?
Yes
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.
*
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.
Place torch near workpiece
and check if pilot arc "jumps"
or transfers to workpiece.
Check work clamp connec-
tion. *Check Control board
PC1 and connections, and
torch and its connections.