Miller 907439002, Руководство пользователя

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General
OM-249474 Page 25
7-8. Removing Cover and Measuring Input Capacitor Voltage
!
Turn Off welding power
source, and disconnect in-
put power.
!
Significant DC voltage can
remain on capacitors after
unit is Off. Always check the
voltage as shown to be sure
the input capacitors have
discharged before working
on unit.
Turn Off welding power source, and
disconnect input power.
Remove cover
1
Interconnect Board PC2
2 Voltmeter
Measure the DC voltage across the
+ bus terminal and − bus terminal on
PC2 as shown until voltage drops to
near 0 (zero) volts. Measure input
capacitor voltage on both inverter
assemblies before proceeding.
.
If the capacitor voltage does
not drop to near zero after
several minutes, use a bleeder
resistor of between 25 and
1000 ohms, at least 5 watts,
#16 AWG 1000 volts DC
insulating rating wire to
discharge the capacitor(s) .
3 Typical Bleeder Resistor
An example of a typical bleeder
resistor is shown on this page.
Proceed with job inside unit.
Reinstall cover when finished.
Tools Needed:
5/16 in.
802 985 / Ref. 245 768-C
1
2
+ lead to left bus terminal, − lead to right bus terminal
1
2
+ lead to left bus terminal, − lead to right bus terminal
3
Typical Bleeder Resistor
#16 AWG 1000 volts
DC insulation rating,
approx 3 in (76 mm)
leads
25 to 1000 ohm, 5
watt resistor