Miller Electric Big Blue 400 PX Welding System User Manual


 
OM-229 979 Page 41
8-12. Optional Voltmeter/Ammeter Help Displays
Use the Voltmeter/Ammeter help
displays to diagnose and correct
fault conditions.
. When a help code is displayed
normally weld output has
stopped but generator power
output may be okay.
. To reset help displays, stop
unit and then restart. See item
6 below to reset Help 25 dis-
play.
1 Help 20 Display
Indicates a failure of meter display
module PC2, or the wiring between
PC2 and main control module PC1.
If this display is shown, have Facto-
ry Authorized Service Agent check
PC1, PC2, and the wiring between
PC1 and PC2.
2 Help 21 Display
Indicates thermistor TH1 on the
main rectifier heat sink has failed.
If this display is shown, have Facto-
ry Authorized Service Agent check
TH1, and the wiring between TH1
and PC1.
3 Help 22 Display
Indicates the rectifier heat sink has
overheated. If this display is shown,
check generator cooling system
and/or reduce duty cycle. Keep en-
gine access door closed when run-
ning to maintain proper cooling air
flow past rectifier. Allow unit to cool
before restarting. If problem contin-
ues, have Factory Authorized Ser-
vice Agent check unit.
4 Help 23 Display
Indicates one of the rectifier output
SCR’s has failed. If this display is
shown, have Factory Authorized
Service Agent check the rectifier
SCR’s.
5 Help 24 Display
Indicates weld open circuit voltage
(OCV) is too high (above 41 volts
dc). If this display is shown, have
Factory Authorized Service Agent
check main control module PC1.
6 Help 25 Display
Indicates a remote device con-
nected to Remote Receptacle
RC14 may be faulty. Help 25 is also
displayed whenever a remote de-
vice has been connected to RC14
and then disconnected. Clear fault
by stopping and restarting the unit
or by turning Process/Contactor
switch to another position. If prob-
lem continues, have Factory Autho-
rized Service Agent check the re-
mote device, filter board PC6, and
main control module PC1.
2
1
HL.P
22
HL.P
23
HL.P
24
HL.P
25
HL.P
20
HL.P
21
6
5
4
3
Ref. 804 630-A