Miller Multimatic 255 - Page 63

OM-278174 Page 59
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Complete Parts List is available at www.MillerWelds.com
Message Error Remedy
The control board is damaged.
Thermal error-Boost module thermis-
tor is shorted.
The boost module thermistor is reading too high
for a valid temperature.
Contact Miller Electric authorized service
location
The control board is damaged.
Thermal error-Boost module thermis-
tor open.
Ambient temperature is too cold for valid
reading.
Place unit in environment warmer than –30°F (–
22°C).
The boost module thermistor is reading too low
for a valid temperature.
Contact Miller Electric authorized service
location.
The control board is damaged.
Thermal error-Inverter module ther-
mistor is shorted.
The inverter module thermistor is reading too
high for a valid temperature.
Contact Miller Electric authorized service
location
The control board is damaged.
Thermal error-Inverter module ther-
mistor open.
Ambient temperature is too cold for valid
reading.
Place unit in environment warmer than –30°F (–
22°C).
The inverter module thermistor is reading too low
for a valid temperature.
Contact Miller Electric authorized service
location.
The control board is damaged.
Thermal error-Secondary magnetics
thermistor is shorted.
The secondary magnetics thermistor is reading
too low for a valid temperature.
Contact Miller Electric authorized service
location
The control board is damaged.
Thermal error-Secondary magnetics
thermistor is open.
Ambient temperature is too cold for valid
reading.
Place unit in environment warmer than –30°F (–
22°C).
The secondary magnetics thermistor is
unplugged.
Contact Miller Electric authorized service
location.
The secondary magnetics thermistor is reading
too high for a valid temperature.
The control board is damaged.
Thermal error-Output rectifier thermis-
tor is shorted.
The output rectifier thermistor is reading too high
for a valid temperature.
Contact Miller Electric authorized service
location
The control board is damaged.
Thermal error-Output rectifier thermis-
tor is open.
Ambient temperature is too cold for valid
reading.
Place unit in environment warmer than –30°F (–
22°C).
The output rectifier thermistor is unplugged. Contact Miller Electric authorized service
location.
The output rectifier thermistor is reading too low
for a valid temperature..
The control board is damaged.
Boost Error
Cycle power to clear error
*Vbus Top High *Vbus Bottom High
*Vbus Balance *Precharge *Initial
Boost Check *Current Sensor 1 *Over
Current *Precharge Relay Failure
The primary boost has not successfully been
established.
Cycle power to clear error. If this error persists
after a power cycle, contact Miller Electric Mfg.
authorized service location.
Cycle power to clear error +15V or –
15V * Primary Error *Boost Error *In-
verter Error
Over voltage-Cycle power to clear. Primary voltage is above 690 volts. Reduce primary voltage below 690 volts.
Under voltage-Cycle power to clear. The primary voltage is below 150 volts. Increase primary voltage above 150 volts.
Network error-Inverter Communication
is down.
The two microcontrollers on the control board
are no longer communicating.
Cycle power to clear error. If this error persists
after a power cycle, contact Miller Electric Mfg.
authorized service location.
Network error-Primary Communica-
tion is down.
Network error-Communication be-
tween UI and control boards is down.
The wiring harness between the control board
and interface board is damaged.
Contact Miller Electric Mfg. authorized service
location.
The primary control board is damaged.
The interface board is damaged.
Stuck Electrode Stick welding electrode has become stuck in
weld puddle and turned output off.
Remove Stick electrode from workpiece and out-
put will turn back on after about one second.
Stuck Tungsten
Tungsten electrode has become stuck in weld
puddle and turned output off.
Remove the tungsten from workpiece and output
will turn back on after about one second.