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CIRCUIT BREAKERS INTRODUCTION

Circuit breakers are the modern equivalent of the fuse (see later section). Indeed, they are much more popular, though many electricians feel that fuses are safer.

The reason for the popularity of the breaker is convenience: a flip or push of a switch can get a circuit going again, rather than having to unscrew a fuse and screw in a new one.

A circuit breaker senses overload and trips out to avoid overheating a wire and possibly causing a fire. At the heart of its construction is a bimetallic strip linked to a couple of springs and contact points. When a circuit becomes overloaded or a short occurs, this strip bends and pulls away from the contact points, breaking the circuit. The electrical flow shuts down. When the breaker lever is reset, the strip is pushed against the contact points and electrical flow starts again.

Two types of circuit breakers are common: those that snap in place and those that screw in place.

If you want to replace a breaker, you sometimes must get a direct replacement unit from the same manufacturer. To find out the name, look on the box door or on the box itself. In many cases, however, circuit breakers are interchangeable. To ensure that you get the right size, take the old circuit breaker to the store.

It should be emphasized that only the experienced do-it-yourselfer should replace a circuit breaker.

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