There are Main Types of Circuit Breakers which widely used in House Wiring and these domestic Electrical Circuit Breakers provide essential protection to house from electrical hazards can be occurs.It is essential to use domestic circuit breakers to get protected from electrical overloads and under abnormal conditions.The most widely used electrical circuit breakers for domestic electrical connections are Miniature circuit breakers (MCBs) ,Residual current circuit breaker (RCCB) and Mounded Case Circuit Breaker (MCCB)Following are some basic guide on these domestic Circuit Breakers.
Main Types of Circuit Breakers
Miniature Circuit Breakers (MCB)
Miniature circuit breakers (MCBs) are fitted in newer consumer units in place of fuses and this is one of main types of circuit breakers which widely used and application of Miniature circuit breakers (MCBs) take necessary part in house wiring .They have the advantage that they can be manually reset without having to replace wire as in the case of the traditional fuse. The MCBs have either a button or lever that can be flicked to reset it.Rated current not more than 100 A in Miniature circuit breakers (MCBs). Trip characteristics normally not adjustable. Thermal or thermal-magnetic operation. Breakers illustrated above are in this category.
The MCB tripping is an indication either that the circuit has been overloaded or that a short circuit has occurred somewhere in the system. Before resetting the MCB it is important to identify what has caused it to trip. Switch off all the appliances connected to the circuit to ensure it is not overloading.
If you find any fault in MCB First switch off the main switch on the consumer unit, this is very important. Reset the MCB by either pushing the button or by flicking the lever.
Finally flick the main switch of the consumer unit back on. If the MCB immediately resets itself once power is restored, then a fault is still occurring, see identifying a faulty circuit to try to identify the fault.
Residual Current Circuit Breaker (RCCB)
Residual current circuit breaker (RCCB) is an electrical wiring device that disconnects a circuit whenever it detects that the electric current is not balanced between the energized conductor and the return neutral conductor.
Such an imbalance is sometimes caused by current leakage through the body of a person who is grounded and accidentally touching the energized part of the circuit.
A residual current circuit breaker cannot remove all risk of electric shock or fire. In particular, an RCD alone will not detect overload conditions, phase to neutral short circuits or phase-to-phase short circuits.
Mounded Case Circuit Breaker (MCCB)
A Mounded Case Circuit Breaker (MCCB) breaker will automatically trip when the current through it exceeds a pre-determined value.
In lower current ratings, automatic tripping of the circuit breaker is accomplished by use of thermal tripping devices.
A circuit can be connected or disconnected using a circuit breaker by manually moving the operating handle to the ON or OFF position. The mounded-case circuit-breakers are used in industrial and civil low voltage plants with service currents from 1 to 1000 A.
They are used in direct and alternating current distribution switchboard, for motor protection (Motor Control Center), generators, capacitors and for end users. It is normally installed very close to the energy meter and should be readily accessible to the consumer.
The over load and instantaneous tripping elements are adjustable over the wide band make. The molded case circuit breakers are the important units used in electrical protection and control. The switching mechanism is enclosed in the mounded case.
Molded case circuit breakers come in a wide range of sizes and current ratings. There are six frame sizes available: 100, 225, 400, 600, 800, and 2,000 amps.
The size, contact rating, and current interrupting ratings are the same for all circuit breakers of a given frame size. The continuous current rating of a breaker is governed by the trip element rating.
