Miller XMT 450 CC, Техническое руководство, Страница: 49 / 84

Always check unit before applying power (see Section 10-1).
TM-257 220 Page 45 XMT 450 CC/CV
Trouble Remedy
Erratic or improper weld output. Use proper size and type of weld cable (see Section 4-2).
Check for proper input and output connections.
Check input and output voltages of hall device HD1. Replace HD1 if necessary.
No 24 volts AC output at Remote 14
receptacle RC50. Reset supplementary protector CB2 if necessary (see Section 4-5).
Check receptacle wiring and connections.
Fan motors do not run after approxi-
mately four minutes of operation at
rated load. Check and clear blocked fan blades.
Check fan motors FM1 and FM2, and replace if necessary.
Check control board PC1 and connections, and replace if necessary (see Section 10-13).
10-10. Help Codes
Display Example
HELP
1
Display
Code
Fault Description Probable Cause(s) Potential Solution(s)
Help 1 Primary Power Cir-
cuit Over Current.
LED1 is lit on
Inverter Control
Board PC1.
Primary IGBTs exceeded
peak current limit of 350
amperes. IGBTs PM1 or PM2 malfunc-
tioning. Check IGBTs per Sec-
tion10-4. Replace PM1 and
PM2 as necessary.
One or more output diodes
D1 thru D4 malfunctioning. Check diodes per Section
10-6. Replace D1 thru D4 as
necessary.
Inverter Control board PC1
malfunction. Replace PC1.
Tank capacitor C1 or C2 mal-
functioning. Check indicated value of C1
and C2.
Current transformer CT1
malfunctioning. Check CT1 for a resistance
of 5 ohms. Replace CT1 if
necessary.
Help 2 Temperature Sen-
sor Malfunction
Shorted or open thermistor. Either thermistor RT1 or RT2
is open or shorted.
Thermistor resistance will
have dropped to <130 ohms
(shorted) or will have risen to
>1.2M ohms (open). Replace faulty thermistor.
Wiring malfunction. Check condition of wiring.
Front panel display board
PC3 malfunction. Replace PC3.