Miller CST 280 - SECTION 7 - MAINTENANCE AND TROUBLESHOOTING; Troubleshooting (Continued)

OM-258 035 Page 31
7-3. Troubleshooting (Continued)
Repeated LED Flashes Indicate
Status
Display
Code
Blue Yellow
Red
(LED1
On
PC13)
Trouble Possible Causes Remedy
H05 5 0 11
No weld output.
Voltage loss.
Vfb leads not connected
or reversed.
Check Vfb leads for proper wiring
and connection to output studs and
PC13.
Short circuit across output
studs.
Check for shorts.
Faulty IGBT PM1 or PM2
on PC2.
Check PC2 and replace if
necessary.
Faulty PC13. Replace PC13.
Low OCV
initially, but
when load is
applied LEDs
begin to flash.
Faulty PM1 or PM2 on
PC2 .
Replace PC2.
Faulty C3. Replace C3.
H02 2 0 6
Reduced weld
output.
Output
foldback due
to excessive
input
current.
Single phase rating
exceeded.
Reduce output to 200 amperes or
less.
High output VA coupled
with a low 230V line.
Check line voltage and weld
settings.
H03 3 0 10 No weld output. Remote trigger has been left on.
Remove trigger, wait approximately
5 seconds, and restart.
H07 0
On
continuously
3
No weld output.
Unit over-
heated.
Primary (IGBT) thermistor
over temperature in PM1
or PM2 on PC2.
Allow unit to cool down.
Retorque PM1, PM2, and PM3
mounting hardware to 25 in lbs
(2.8 Nm).
5
Secondary thermistor
over temperature on
output diode heatsink.
H08 0
Flashes
continuously
0
No weld output.
Thermistor
failure.
Shorted primary (IGBT)
thermistor in PM1 or PM2
on PC2.
Check IGBT PM1 and PM2
thermistors on PC2 for shorts.
2
Open primary (IGBT)
thermistor in PM1 or PM2
on PC2.
Check IGBT PM1 and PM2
thermistors on PC2 and associated
wiring for opens.
4
Open secondary
thermistor on output diode
heatsink.
Check thermistor on output
heatsink and associated wiring for
opens.
9
Shorted secondary
thermistor on output diode
heatsink.
Check thermistor on output
heatsink and associated wiring for
shorts.
N/A N/A N/A
Fan not
operating.
Blocked fan.
Check for and remove anything
blocking fan movement.
Fan failure.
Have factory authorized service
agent check fan motor.
Faulty PC13. Replace PC13.
N/A N/A N/A
Fan cycles on
and off.
Over voltage condition.
Check primary voltage and Voltage
Selection switch.
Faulty voltage sense circuit on PC2. Replace PC2.
N/A N/A N/A
Erratic or
improper weld
output.
Weld cables too small or defective.
Use proper size and type of weld
cables (see Section 5-2).
Dirty or loose connections.
Clean and tighten all weld cable
connections
(see Section 5-4 or 5-5).
N/A N/A N/A Wandering arc.
Improper tungsten.
Use proper size tungsten
(see Section 9-1).
Worn or defective tungsten.
Use properly prepared tungsten
(see Section 9).
Gas flow too high.
Reduce gas flow rate
(see Section 5-4).
N/A N/A N/A
Tungsten
electrode
oxidizing and
not remaining
bright after
conclusion of
weld.
Gas is blown away from weld zone. Shield weld zone from drafts.
Inadequate postflow time.
Allow adequate postflow time to
shield tungsten while it is cooling
after welding stops.
Loose or leaking gas fittings.
Check and tighten all gas fittings
(see Section 5-4).
Water in torch. Refer to torch manual.