Troubleshooting - Miller CST 280 Owner's Manual

7-3. Troubleshooting

Repeated LED Flashes Indicate
Status
Display
Blue Yellow
Code
None (Prior to
(Prior to
MA050
MA050
280G)
Alternating Alternating
Blue And Blue And
Yellow (Eff Yellow (Eff
H09
w/MA050280 w/MA050
G)
Flashes
H01
Continuously
H06 6
H04 4
OM-258 035 Page 30
1
2
Red
(LED1
Trouble
On
PC13)
None
No weld output;
None unit completely
inoperative.
280G)
No weld output;
12 unit completely
inoperative.
280G)
0 7 No weld output.
0 1 No weld output.
0 8 No weld output.
Possible Causes
Line Disconnect open.
Improper input connections.
Incorrect input voltage depending on
Voltage Selection Switch position. PTC1
and PTC2 on PC2 overheated due to when
unit was turned on.
Process Select switch is between posi-
tions.
Line voltage too high or
too low.
Unit is linked incorrectly.
Not ready.
Buss voltage imbalance.
No primary lfb.
Faulty output diode(s) D1
or D2.
Faulty boost inductor L3.
Over-current
Faulty HD1.
fault.
Open connection between
HD1 and PC1 or PC13.
Faulty PC13.
Faulty PC2 (239001 or
245857)
Shorted boost relay CR1.
Boost relay CR1 does not
de−energize after ter-
Over-voltage
mination of weld.
latch.
Voltage in excess of 100V
from another source ap-
plied across output studs.
1 Output LED (Blue)
2 High Temperature LED
(Yellow)
258 649-A
Remedy
Place line disconnect switch in on
position
(see Section 5-9 or 5-10).
Check for proper input
connections
(see Section 5-9 or 5-10).
Turn off welding power source,
open rear switch cover, and turn
Voltage Selection Switch to correct
input voltage. Allow a 10 minute
cooling down period before turning
welding power source back on
again.
Verify Process Select switch is not
between positions.
Line voltage must be ±10%.
Check line voltage and link
accordingly.
Check DC buss caps and PC2, and
replace if necessary.
Check CT1 and wiring for an open
condition.
Check for shorts or opens in wiring.
Replace boost inductor L3 if
necessary.
Replace HD1 if necessary.
Inspect all wiring and
connections.
Replace PC13.
Replace PC2.
Check for a shorted relay CR1 or
wiring.
Check PC13.
Check for external voltage sources.