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VM1/A/P
- INSTALLATION AND SERVICE INSTRUCTIONS ANSI: ... 15 KV; ... 2000 A; ... 31.5 K A
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8. Maintenance
8.11. Control wiring
During routine maintenance for control wiring, a
visual inspection of the hardware should be
performed and a low-frequency withstand voltage
testing performed, and 2-5 manual operations
should be conducted. Disconnect control power
before verifying secondary hardware and before
low-frequency withstand voltage testing.
Remove the front cover with a screwdriver. Correct
any loose or missing mounting hardware. Verify the
ground wire connection to the frame and all
connectors’ alignment and snugness on the
electrical components. Visually inspect the
secondary plug and correct any pins that may have
become displaced.
To verify the integrity of the secondary insulation,
perform the following low-frequency withstand
voltage test:
1. Disconnect control power.
2. Connect all pins from the secondary to a test
wire.
3. Connect test wire to the high potential lead of
the test machine.
4. Ground the circuit breaker frame.
5. Start machine with output potential at 0 (zero)
VAC RMS.
6. Increase the potential to the required insulation
test voltage (1125VAC RMS).
7. Hold for one minute.
8. Reduce potential to 0 (zero) VAC and turn off
machine.
A successful withstand testing indicates
satisfactory insulation strength of the secondary
circuit. Failing insulation will not sustain the voltage
across the secondary. Replace the circuit breaker
control wiring if the insulation fails during low-
frequency withstand voltage testing.
Replace the front cover before operation. Verify the
operation with 2-5 electrical operations in the Test
position or with a remote power supply.
8.12. Primary circuit assembly: (Pole)
During routine maintenance for the primary circuit,
a visual inspection of the hardware and a low-
frequency withstand voltage testing, and
lubrication of the primary contacts should occur as
outlined hereinafter.
All insulation material should be clean and free of
structural cracks. Inspect for structural cracks and
replace damaged parts.
Dirt or dust may create a dielectric path to ground
on the insulation. Remove dust and dirt with a
clean, lint-free cloth. Apply distilled water to the
cloth to remove any difficult dirt. DO NOT return the
circuit breaker into service until the insulation
surfaces are completely dry .
Lubrication on the primary contacts should be
inspected during routine maintenance. Use only
grease ISOFLEX TOPAS NB52 (ABB
GCE0007249P01001PLCRN).
CAUTION
Applying abnormally high voltage across a
pair of open contacts in a vacuum may
produce x-radiation.
The radiation may increase with the increase
in voltage and/or decrease in contact
spacing. It is recommended that all
operating personnel stand at least one
meter away and in from of the circuit breaker
during testing.
Summary of Contents for VM1/A/P
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