DISTRIBUTION SOLUTIONS
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7.8. Earthing
For the fixed version circuit breaker, carry out
earthing by means of the special screws marked with
the relative symbol (see fig. 4).
Clean and degrease the area around the screw to a
diameter of about 30 mm and, on completion of
assembly, cover the joint again with Vaseline grease.
Use a conductor (busbar or cord) with a cross-
section conforming to the Standards in force.
7.9. Connection of the auxiliary
circuits
Note: the minimum cross-section of the wires used
for the auxiliary circuits must not be less than the one
used for the internal cabling. Furthermore, they must
be insulated for 3 kV test.
Please note that auxiliary circuits must be energized
with 2 kV (maximum test voltage) as per standards
indications.
7.9.1. Fixed circuit breaker
Connection of the circuit breaker auxiliary circuits
must be made by means of the proper terminal box
mounted inside the circuit breaker and the wires
must pass through the connector (2). Outside the
connector, the cables must pass through a suitable
metal protective covering (pipe, wiring duct, etc.) and
be earthed.
To prevent the cabling wires outside the circuit
breaker (provided by the customer) from accidentally
coming into contact with moving parts and therefore
damaging the insulation, the wires should be
positioned and fixed as shown in the figure.
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.
7.9.2. Withdrawable circuit breakers
The auxiliary circuits of withdrawable circuit breakers
are fully cabled in the factory as far as the connector
(1 - fig. 11).
For the external connections, refer to the electric
wiring diagram of the switchgear.
Fig. 10
Fig. 11
Before removing the operating
mechanism cover to access the terminal
box, check that the circuit breaker is
open and the closing springs
discharged.
Summary of Contents for Vmax 12
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