Preliminary Operations - ABB VD4 36 Installation And Service Instructions Manual

7.3.

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.
7.4. 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.
7.4.1. Mounting the circuit-breaker on a truck made by
other manufacturers
The VD4 circuit-breakers which are not installed on ABB
trucks, but on trucks made by the customer, must be fitted
with one or two additional auxiliary contacts (activated by the
mechanical lock and by the circuit-breaker release device) to
carry out the function of interrupting the shunt closing release
circuit (-MC) during traverse from isolated and vice versa.
In ABB trucks, this function is carried out by the -BT1 and
-BT2 auxiliary contacts which cut of the release power supply
during and before activation of the mechanical lock of the
screw truck racking-in device. This means that the shunt
closing release power supply can only by applied at the end
of activation of the mechanical lock. In this way it is certain
that no electrical impulse can activate the shunt closing
release with the circuit-breaker in an intermediate position.
7.5. Installation of withdrawable circuit-
breakers in UniGear ZS2 switchgear and
PowerCube modules
The withdrawable circuit-breakers are preset for use in
UniGear ZS2 switchgear and PowerCube modules.
For racking-in/racking-out of the switchgear, fully insert
the lever (1) (fig. 9) in the appropriate seat (2) and work it
clockwise for racking-in, and anti-clockwise for racking-out,
until the limit switch positions are reached.
Circuit-breaker racking-in/-out must be carried out gradually
to avoid shocks which may deform the mechanical interlocks
and the limit switches.
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 30 rotations of the lever are
required for circuit-breakers.
When the circuit-breaker has reached the isolated for test/
isolated position, it can be considered 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.
However, when, for example, different electrical accessory
fittings are provided, a different code for the plug of the
auxiliary circuits does not allow incorrect combinations
between panels and circuit-breakers.
For the circuit-breaker installation operations, also refer to the
technical documentation of the above-mentioned switchgear.
• The racking-in/-out operations must always be
carried out with the circuit-breaker open.
• When putting into service for the first time, it is
advisable to charge the circuit-breaker operating
mechanisms manually so as not to overload the
auxiliary power suply circuit.
18