40
VM1
- USER MANUAL
—
9. Installation
9.3. Preliminary operations
•
Clean the insulating parts with clean dry cloths.
•
Check that the top and bottom terminals are clean
and free of any deformation caused by shocks
received during transport or storage.
9.4. Installation of fixed circuit
breakers
The circuit breaker can be mounted directly on
supporting frames to be provided by the
customer, or on a special supporting truck
(available on request).
The circuit breaker, with supporting truck, must
be suitably fixed to the floor of its own
compartment by the customer. The floor surface
in correspondence with the truck wheels must be
carefully levelled.
A minimum degree of protection (IP2X) must be
guaranteed from the front towards live parts.
9.5. Installation of withdrawable
circuit breakers
The withdrawable circuit breakers are preset for
use in UniGear switchgear or PowerCube modules.
For racking-in/racking-out of the switchgear:
connect the auxiliary circuits thereby supplying
the locking electromagnet in the truck, fully insert
the crank handle (1) (fig. 13) in the appropriate
seat (2) and work it clockwise for racking-in, and
anti-clockwise for racking-out, until the end-of-
run positions are reached. Circuit breaker racking-
in/-out must be carried out gradually to avoid
shocks which may deform the mechanical
interlocks and the end-of-runs.
The torque normally required to carry out
racking-in and racking-out is < 25 Nm.
This value must not be exceeded. If operations are
prevented or difficult, do not force them and
check that the operating sequence is correct.
Note
To complete the racking-in/out operation, about 20 turns of the crank
handle are required for circuit breakers up to 17.5 kV, and about 30 turns
for 24 kV circuit breakers.
When the circuit breaker has reached the isolated for test/isolated
position it can be considered as racked into the switchgear and, at the
same time, earthed by means of the truck wheels.
Withdrawable circuit breakers of the same version, and therefore with the
same dimensions, are interchangeable.
For the circuit breaker installation operations, also refer to the technical
documentation of the above-mentioned switchgear.
9.5.1. Circuit breakers with withdrawable
motorized truck
Carry out the racking-in/racking-out test of the
motorized truck in the same way as for a manual
truck, following the instructions below:
•
Rack the circuit breaker into the switchgear in the
open and isolated position, with the power supply
to the motor circuit cut off and with the enclosure
door closed.
•
Insert the manual racking-in lever (1) in the special
coupling (2) Fig. 13, and take the motorized truck
to about half its run between the isolated for test
and the connected position.
The torque needed to carry out truck handling is
<25 Nm.
In the case of accidental inversion of the truck
motor power supply polarity, this operation allows
a possible error in direction to be dealt with
without any damage. Verification checks:
•
a) motor rotation
clockwise
during circuit breaker
racking-in.
•
b) motor rotation
anticlockwise
during circuit
breaker racking-out.
- Remove the manual lever (1) from the coupling
(2) Fig. 13
- Supply the truck motor circuit and wait for the
LED on the front of the circuit breaker signalling
unit
“ready”
to come on permanently.
- Activate the control for the electrical racking-in
operation. When racking-in has taken place,
check correct changeover of the relative auxiliary
contact.
- On completion, activate the control for the
electrical racking-out operation. When racking-
out has taken place, check correct changeover of
the relative auxiliary contact.
- In the case of a motor fault during a racking-in or
racking-out operation, in an emergency the truck
can be taken to the end of its run manually, after
first cutting off the power supply to the motor
power supply circuit and then, using the manual
lever, work in the same way as with the manual
truck.
- In the case of a locking magnet –RL2 fault, in an
emergency the truck can be racked out manually
following the instructions below:
- cut off the power supply to the motor circuit
- open the enclosure door
- remove the circuit-breaker front protection
shield
- using the manual lever, carry out an emergency
racking-out operation, keeping the moving
anchor of the locking magnet –RL2 pressed
down by means of a screwdriver during the
initial stage of racking-out (Fig. 13a).
The racking-in/-out operations must
always be carried out with the circuit
breaker open.
Summary of Contents for VM1
Page 59: ...MEDIUM VOLTAGE PRODUCTS 59 59 ...
