DISTRIBUTION SOLUTIONS
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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 fixed directly on the
supporting plate or on a truck provided by the
customer. The customer must guarantee a minimum
degree of protection (IP2X) from the front towards
live parts.
Note: the circuit breakers for UniGear switchgear with fixed CB are installed
directly in the factory – the Customer is not required to carry out any
activities.
7.5. Withdrawable circuit breakers
with truck made by third
parties
The Vmax circuit breakers installed on trucks made by
the customer must be fitted with one or two
additional auxiliary contacts (operated by the
mechanical lock and by the circuit breaker release
device) which are entrusted with the function of
interrupting the shunt closing release circuit (-MBC).
In this way it is certain that no electrical impulse can
activate the shunt closing release with the circuit
breaker in an intermediate position.
The customer must also provide a lock to prevent
circuit breaker traverse when it is in the closed
position.
7.6. Withdrawable circuit breakers
with ABB truck for UniGear ZS1
550 mm wide, and UniSec
switchgear
The withdrawable circuit breakers are preset for use
in UniGear type ZS1 switchgear 550 mm wide.
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
might 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: about 20 rotations of the lever are required to complete the racking-in/
out operation.
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.
630 A and 1250 A withdrawable circuit breakers are
interchangeable dimensionally. Thanks to different
coding of the auxiliary circuit plug, incorrect
combinations between panels and circuit breakers
are prevented.
For the circuit breaker installation operations, also
refer to the technical documentation of the above-
mentioned switchgear.
Max. 25 Nm
Racking-in
Racking-out
The racking-in/-out operations must
always be carried out with the circuit
breaker open.
Summary of Contents for Vmax 12
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