Accessories
4.4 Plug-in and draw-out technology
3VA molded case circuit breakers
Manual, 04/2015, A5E03603177010-02
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Plug-in and draw-out technology
4.4.1
With most applications, 3VA molded case circuit breakers are installed in a fixed position in
switchboards or distribution boards. The breaker is normally secured by fastening bolts
directly to the mounting plate or other suitable supporting stays of the cubicle. The cables or
busbars of the main circuits are connected directly to the 3VA molded case circuit breaker by
various terminals or connectors. A rigid, permanent connection is thus created between the
3VA molded case circuit breaker and the cubicle.
With certain applications such as those where regular maintenance and overhaul of circuit
breakers is required, for example, it must be possible to replace the 3VA molded case circuit
breakers quickly. To meet this requirement, 3VA molded case circuit breakers can be
converted to plug-in and draw-out units.
The main differences between plug-in units and draw-out units are convenience of operation
and the potential for functional expansion.