6
7
8
1
1.1
1.2
1.3
10
3
4
2
9
11
5
20
VM1/A/P
- INSTALLATION AND SERVICE INSTRUCTIONS ANSI: ... 15 KV; ... 2000 A; ... 31.5 K A
—
6. Description
6.1. Basic structure of the
withdrawable circuit breaker
(Fig.10a)
The withdrawable truck (9), consists of a steel sheet
structure with wheels (3), on which the circuit
breaker with the relative auxiliary components, the
isolating contacts (10) for electrical connection
with the switchgear and the multi-pole secondary
connector (1) for connection of the circuit breaker
auxiliary circuits are installed.
After having been racked into the switchgear and
hooked up, the withdrawable circuit breaker can
take up the following positions: racked-out,
isolated for test (with connector inserted) and
racked-in. The racked-in circuit breaker is
automatically earthed by means of the truck wheels.
The magnetic actuator of the circuit breaker and
the relative controls and indicators, are accessible
from the front. Withdrawable circuit breakers of the
same type and characteristics are interchangeable.
However, the code of the connector prevents
incorrect combinations between the circuit breaker
and switchgear.
6.2. Circuit breaker structure of the
circuit breaker (Fig.10b)
The encapsulated poles are installed on the rear flat
section of the circuit breaker frame (1.1. Fig. 10a).
The live parts of the circuit breaker poles are
enclosed in cast resin and protected from impacts
and other external influences.
With the circuit breaker closed the current path for
each pole leads from the upper circuit breaker
terminal (1) to the fixed contact (2a) in the vacuum
interrupter (2), then via the moving contact (2b) and
the flexible connector (5) to the lower circuit
breaker terminal (4).
The change of contact state is delivered by means
of the insulated link rod (7) with internal contact
force springs (6).
5. Mechanical operating cycle counter
6. Mechanical CLOSE/OPEN indicator
7. Rating plate
8. Socket for emergency manual operation
9. Truck
10. Primary isolating contacts
11. Wheels
Fig. 10a
1. Secondary plug connector
1.1. Breaker frame
1.2. Front Plate
1.3. Slot for handling, both sides
2. “Ready” indicator
3. CLOSE push- button
4. OPEN push-button
Summary of Contents for VM1/A/P
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