Accessories
4.4 Plug-in and draw-out technology
3VA molded case circuit breakers with UL and IEC certification
Manual, 01/2019, L1V30435333-01
239
The plunger performs various safety functions in operation:
●
It prevents closure of the main contacts of the molded case circuit breaker when the
breaker is inserted in the draw-out socket and in an undefined position (breaker status
indication is UNBLOCK).
●
It allows the breaker to be closed in the defined positions TEST and CONNECT.
●
It trips the molded case circuit breaker (TRIP) when the breaker's main contacts are
closed (switching position ON) and an attempt is made to move the breaker out of one of
the three defined positions CONNECT, TEST or DISCON using the crank handle.
Auxiliary circuit connectors
Molded case circuit breakers are frequently equipped with internal accessories, e.g. auxiliary
switches, auxiliary releases, etc. A broad range of components is also available for the
3VA UL molded case circuit breaker. For further information, please refer to chapter Internal
accessories (Page 152).
To ensure that the electrical connections required by draw-out units can be quickly and
safely disconnected, auxiliary circuit connectors can be installed.
The part of the auxiliary circuit connectors on the circuit breaker side is mounted on the
underside of the molded case circuit breaker using the cable cage and is electrically
connected to the internal accessories. Appropriate openings and cable ducts are provided in
the 3VA UL molded case circuit breaker for routing stranded wires. The socket-end half of
the auxiliary circuit connector with the movable telescopic rail is inserted in the socket and
electrically connected to the customer's installation.
When the molded case circuit breaker is inserted into the draw-out unit, an electrical
connection between the internal accessories in the breaker and the customer's installation is
quickly established.
Note
Plug-in and draw-out units use different versions of the auxiliary circuit connector.
The draw-out version has a longer, movable telescopic rail because the distance to be
bridged in the draw-out socket is longer.
Further details about auxiliary circuit connectors can be found in chapter Auxiliary circuit
