Electrical Interlocking of ACB

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An interlocked ACB (air circuit breaker) would be one that disconnects three phases at the same time.

An electrical interlock defeating feature? Sounds like something that would prevent tying several interlocked ACB's together. An electrically controlled interlock would be something that was controlled by a solenoid trip coil. The application of an electrical control signal would then be able to open the ACB remotely.

The problem with opening several ACB's at the same time may have more to do with reducing the risk of an arc flash.

But answering your question accurately really depends on how well it was asked.

Either disconnect or short out the interlock. A defeat is something that wouldn't normaly be provided, it's the whole idea of interlocks.

There are many types of interlocking provided...you would need to specify which one/s you mean.

Typical ones are

Within the ACB -

(a) prevention of closing command when there is a trip command already present.

(b) prevention of closing command when the spring/s are not completely charged.

(c) prevention of plugging in / withdrawing an ACB which is ON.

(d) etc...

Between two or more ACBs :

(a) prevention of more than necessary ACBs being ON at the same time eg., One incomer + one bus coupler only.

(b) etc.

It is never good practice to defeat these interlocks, but in some specific situations, an authorised and qualified person may be empowered to do so. Case to case basis.

A simple example is star-delta starters.