Connection Of The Auxiliary Circuits - ABB VD4 36 Installation And Service Instructions Manual

7.7. 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
of test.
7.7.1. Fixed circuit-breaker
Connection of the circuit-breaker auxiliary circuits must be
made by means of the terminal box (1) (fig. 10) mounted
inside the circuit-breaker and the cables must pass through
the connector (2).
1
Fig. 10
Outside the connector, the cables must pass through a
suitable metal protective cover (pipe, wiring duct, etc.), which
must be earthed.
To prevent the cabling wires outside the circuit-breaker
(carried out by the customer) from accidentally coming into
contact with moving parts and therefore undergoing damage
to the insulation, it is recommended to fix the wires as shown
in fig. 10a.
Before removing the operating mechanism cover
to access the terminal box, check that the circuit-
breaker is open and the closing spring discharged.
7.7.2. Withdrawable circuit-breakers
The auxiliary circuits of withdrawable circuit-breakers are fully
cabled in the factory as far as the connector (fig. 11).
For the external connections, refer to the electric wiring
diagram of the switchgear.
2
VD4 circuit-breaker for UniGear switchgear
and PowerCube module.
20