Miller XMT 450 CC, Техническое руководство, Страница: 43 / 84

PRE-POWER CHECKS
TM-257 220 Page 39 XMT 450 CC/CV
10-3. Input Rectifier SR1
Ref. 255 761-A
!
Read and follow safety
information in Section 10-1
before proceeding.
!
Wear an earth grounded
wrist strap when performing
pre-power and power off
checks. Remove wrist strap
before performing any
checks or procedures with
power applied to the ma-
chine.
Input Rectifier SR1
AC (L3)
AC (L2)
AC (L1)
Positive (+)
Terminal L1-2
Location On
PC2
Negative (−)
A
B
C
D
E
F
Input rectifier SR1 is a 3 phase diode module with 6 internal diodes, 2 diodes for each phase. SR1 is located between the right heat sink and
the large vertical power interconnecting board PC2.
1. Visually inspect SR1 for damage. If there is visual evidence of damage such as smoke/debris or found to be defective using this procedure,
replace SR1.
2. Check the six input rectifier diodes within SR1 (using diode check on DMM). Look for a diode drop of .2 to .9 VDC across the following test
points on PC2:
Positive Meter Lead Negative Meter Lead
A (AC Line 1) D (+)
B (AC Line 2) D (+)
C (AC Line 3) D (+)
E (−) A (AC Line 1)
E (−) B (AC Line 2)
E (−) C (AC Line 3)
If the input rectifier diodes are defective, check the three poles of the input contactor W1, the DMM should read OL.