Miller XMT 450 CC, Technical Manual, Page: 54 / 84

Always check unit before applying power (see Section 10-1).
TM-257 220 Page 50 XMT 450 CC/CV
10-12. Readings For Troubleshooting Circuit Diagram (All Models)
(Use With Section 10-11)
Resistance Values
a) Tolerance −
±
10% unless specified
b) Turn Off unit and disconnect input power before
checking resistance
R1 thru R7 Less than 1 ohm
R8 5 ohms
R9, R10 Approximately 33k ohms at 68
°
F (20
°
C)
R11 7 ohms
Voltage Readings
a) Tolerance −
±
10% unless specified
b) Reference − to circuit common
(lead 42) unless noted
V1 +565 VDC
V2 400 VAC
V3 24 VAC
V4, V5 18 VAC
V6 115 VAC
V7 24 VAC after precharge
V8, V9 +24 VDC with fans running
(RC7-2, RC8-2 reference)
V10, V11 +282 VDC
V12 +15 VDC
V13 +1 VDC per 100 A of weld
current
V14 −15 VDC
V15 +85 VDC open circuit (negat-
ive stud reference)
in Scratch Start TIG, TIG,
MIG, Pulse MIG CC, Stick,
and V-Sense Feeder modes.
+14 VDC in Lift-Arc TIG
mode when output enabled
and no load applied.
V16 +24 volts DC when gas is
flowing. (RC6-6 reference)
.
+14 VDC in Stick and
Scratch Start TIG modes
when low open circuit
voltage mode is enabled.