Input Rectifier Sr1, Input Capacitors C3 And C4, And Resistors R11 And R12; (200/230/460 V Model Shown) - Miller Millermatic 350P Technical Manual

8-4. Input Rectifier SR1, Input Capacitors C3 And C4, And Resistors R11 And R12

(200/230/460 V Model Shown)

z
L
L
L
z
Millermatic 350
Input Capacitors C3, C4
z
z
L
L
L
L L
L
L
L
z
z
Input Rectifier SR1
L Torque to 25 in/lbs (2.8 NVm)
z Torque to 31 in/lbs (3.5 NVm)
Torque all other hardware
to 17 in/lbs (1.9 NVm)
!
Read and
information in Section 8-1 before
proceeding.
!
Wear an earth grounded wrist
strap when performing pre-power
checks. Remove wrist strap be-
fore performing any checks or
procedures with power applied to
the machine.
Checking Input Rectifier SR1
.
Resistance values are based on in-
circuit measurements.
1 Visually inspect SR1 for damage.
2 Check 6 diodes (diode test). Check
from each AC terminal to the
positive (+) terminal and from each
AC terminal to the negative (−)
Resistor
terminal.
R12
3 If SR1 is defective, check the
contactor W1.
Checking Capacitors C3 And C4
.
This is not a conclusive test. For best
results use a capacitor tester to
check capacitance.
Resistor
R11
.
If either C3 or C4 is shorted, remove
interconnecting board PC2 and
check IGBT's PM1 and PM2.
1 Check C3 and C4 for a short (ohms
position).
Checking Resistors R11 And R12
1 Check R11 and R12, resistance
should be approximately 40 ohms.
If resistors are
contactor W and wiring to contactor.
follow safety
damaged, check
221 044-A / Ref. 803 550-A
TM-1327 Page 45