Circuit breakers are made in varying sizes, from small devices that protect an individual household appliance up to large switchgear designed to protect high voltage circuits feeding an entire city.
We know need rccb match mcb use control home circuit safety, but why we should choose rccb and plat what role in circuit? Now Meba will tell you RCCB working principle and function in circuit.
Principle of operation:
In the event of a short to earth the residual current operating system to prevent shock hazard voltage from remaining on the body of an electrical equipment. For this purpose, the residual current device monitor the difference between the loads flowing through it and ensures that it is aproximately zero. If, as a result of an earth fault, this difference exceeds the circuit breaker’s residual operating current rating ln, then the RCCB will trip and disconnect the circuit of faulty equipment.
● To open a circuit automatically in the event of an earth leakage between phase and earth and/or neutral and earth. With effective protection against human contact to earth points.
● Protection against Direct Contact of persons or livestock with live part.
● Protection against Indirect Contact of persons or livestock with exposed conductive parts which have become live under fault conditions.
● Protection against Electrical Fires caused by high resistance fault arching but not causing the over current protection device to operate.
● Designed with surge current withstand capability to prevent nuisance tripping during thunderstorms. Conditionally surge current proof (250A, 8/20us), without time delayed tripping.
● These devices are sometimes called an ELCB or RCD.
● Use in domestic, commercial and industrial installations.
Even relatively insensitive RCCBs (In 300mA) can effectively safeguard against fires caused by earth leakage faults. In the case of residual currents ( 300mA) the electrical energy converted at the location of the earth fault is insufficient to ignite normal building materials. With higher residual currents, the RCCB will shut down in less than 100ms, thereby restricting the amount of energy released to harmless levels.
The use of RCD on 3 phase 3 wires systems:
The MEBA range of 4 pole RCCBs can be used to provide residual current protection of 3 phase, 3 wire circuits (no neutral). Use terminal “1-2, “5-6”, “N-N”, otherwise the RCCB test circuit will not operate.
Selection of Type A RCCB is recommended to ensure compatible safe operation in the presence of pulsating dc components in the circuit. Household products using inverter power conversion technology needs to be protected with Type A RCCB for efficiency.