Circuit Breakers and Its uses

Circuit Breakers and Its uses 

A circuit breaker is a switching((ON/OFF/TRIP) device that is used for:

1. For switching ON/ OFF the load.
2. For interrupting the circuit under the fault condition.

When the load is switched on or off, the arc is produced between the contacts of the breaker. To quench the arc, the circuit breaker has a medium in which make/ break of the contacts take places. The circuit breaker can be of one of the following types; minimum oil circuit breaker, air circuit breaker, SF6, and vacuum type.

The breaker must be capable to interrupt the fault current at the instant of the short circuit or earth fault. The arc produced during the fault condition is enormous and if the arc is not quenched by the insulating medium then the faulty section cannot be isolated and it can further lead to damage of electrical switchgear, equipment etc.

The breaker must have sufficient short circuit fault interrupting capacity to safely isolate the faulty section. The fault current may be in the order of 20 KA to 40 KA, depending on the fault current of the electrical installation.

Circuit breaker is a safety device used to protect your electrical appliances at home in case of short circuit or any other cause for excessive current. It has replaced the fuses from the earlier days.

Whenever there is excess current in the circuit beyond the max rating, the breaker ‘trips’. You are supposed to switch off everything in the affected area, reset the circuit breaker to ON position, and then try each appliance one by one to check which one is causing the problem. Sometimes, the problem is caused by a high voltage spike in the supply.

If you are electrically challenged, it is best to call a professional electrician.

It serves as an a reusable fuse. When too great of a current load is placed on a circuit, there is a potential risk that the wires will heat up. When conductors have too much current running through them, the relatively narrow diameter wire or cable means there is a lot of resistance to the large current flow and therefore risk of fire.

Unlike a fuse which has a thermally rated conductor inside it that will "open" by simply melting with too much current load and thus turning off the circuit, a circuit breaker when tripped can be reset by moving it back to the on or closed position. No fuse needs to be replaced.

However, whatever caused the circuit breaker to trip, usually overload conditions, the excessive load on the circuit could likely cause it to trip again until something is changed.

There could be too many devices on the circuit with a maximum amperage value of 10 amps or 20 amps, that utilize narrow gage extension cords, with running power tools, space heaters, hair driers, vacuums, or air compressors.

Circuit breakers can eventually go bad too, requiring replacement.