A circuit breaker is a manually operated electric switch designed to prevent excessive current from a short circuit or overload from damaging an appliance. Its main function is to interrupt power flow when a fault is detected. It is essential in electronic appliances and some other equipment where current passing through it is required for the proper operation. It is usually mounted outside the building, either in the ceiling or on the wall close to the circuit breaker.
Circuit breakers are used to regulate current that goes to different parts of the house like room heaters, lights, electric outlets and many other appliances. They are available in different types that include series, single trip, or fuse-operated. The type of circuit breaker is chosen for a certain application will depend on the needs of the appliance, the proximity of the appliance to the circuit breaker, and on the potential for trip or shock hazard when the appliance is operating under higher currents.
There are several kinds of circuit breaker wires. Among them the three most common types are wire bus, metal cable, and coaxial wire bus. Wire bus is the most preferred one for homes. These are made of a flexible plastic material similar to insulating foam or tissue paper. It can withstand extreme temperature and is flexible enough to wrap around the steel core of the breaker.
Circuit breaker with contacts is the most costly kind. These are made of a hard plastic material and are similar to rubber inserts. They allow electricity to flow freely when a fault develops in a circuit without opening the breaker box. This gives protection against shock or fire accident that may be caused by tripping of contacts in the breaker box.
Circuit breaker with fuses are also available. These fuses have terminals that are either touchy or sensitive so that you can find a suitable one for your circuit breakers. You can flip the switch or set the timer for a specific duration to find a fuse that does not start tripping until the circuit breaker has been tripped. But some of these fuses require maintenance and need replacing after heavy duty use.
The range of functionalities offered by electrical appliances is increasing day by day. More advanced technology in circuit breakers can offer the following features: programmable control; memory capability; auto shutdown on tripping of a circuit breaker; integrated thermometers and light indicators for easy monitoring; remote key pads for easy access and control; low power consumption; weatherproof design; dual locking system; and many other useful features. Most of these advanced circuit breakers today have digital LED display which displays the current status and the maximum voltage that the circuit breaker can handle safely. Some also have built-in battery packs that can be charged via AC adapter.
On the other hand, standard circuit breakers are available with metallic bodies and spring loaded contacts. The metallic body is usually made of iron or steel, while the contact contacts are made of rubber. The most important function of the metallic circuit breaker body is that it provides safety against electrical shock. In addition, the body of the breaker contains fuse holders that can hold multiple fused fuse at different locations.
The spring-loaded contacts of a circuit breaker consist of two pieces – one part made of metal and another of soft rubber. When the circuit breaker is tripped, a small amount of current flows between the contacts when the respective contacts are pushed together. The soft rubber piece is placed above the contacts and is pulled down into the hole created by the trip of the breaker. When the circuit breaker trips, the current flow stops and the soft rubber contact breaks, releasing the stored energy. This breaker type offers a very simple mechanism for all types of installations and there is no requirement for service and maintenance apart from the occasional replacement of the fuse holders.