Rccb Circuit Breaker bd

Working Principle of RCCB

An ideal circuit is that currents flows through the circuit via the live wire should be the same as the returning current via the neutral wire.

However, when an earth fault happens, current enters the earth wire by accident such as accidental contact with open wire. As a result, the current returning through then neutral wire is reduced. The difference in current between the live and neutral wire is called residual current. RCCB is designed such way that it continuously senses the residual current or the difference in current values between the live and neutral wires. Therefore, unless the residual current does not surpass the limit, the RCCB will disconnect the circuit.


Types and Ratings

TypesWaveformACSensitive to residual sinusoidal alternating current onlyASensitive to residual alternating current and/or pulsating direct currentBProvide protection of alternating residual sinusoidal current up to 1000Hz, pulsating direct current and smooth direct residual currents.FProvide protection for circuit using single phased variable speed drivers could be used.

Pole types of RCCB: The 2 Pole, The 3 Pole and the 4 Pole.

2 Pole RCCB – Used in case of a single-phase supply connection that has only a live and a neutral wire.
4 Pole RCCB – Used in case of a three-phase supply connection and also an additional connection for the neutral of the supply
Earth Leakage Circuit Breaker, ELCB
This device has the same function as the residual current circuit breaker, RCCB but it is a voltage sensor device. They are suitable for three-phase circuits and high current loads. The residual current level and tripping delay is often adjustable, thus allowing selectivity among different circuit breakers. Regardless, ELCB is an old device and the RCCB has better advantages.

Earth Leakage Circuit Breaker, ELCB
This device has the same function as the residual current circuit breaker, RCCB but it is a voltage sensor device. They are suitable for three-phase circuits and high current loads. The residual current level and tripping delay is often adjustable, thus allowing selectivity among different circuit breakers. Regardless, ELCB is an old device and the RCCB has better advantages.


Ms Power Line Electric
WhatsApp 01711344118
Kaptanbazar complex Dhaka Bangladesh.

What is the function and additional function of RCCB?

Residual Circuit Current Breaker, RCCB
It is a device that has a mechanical switch attached with a residual tripping feature attached to it. As mentioned above, it will only break the circuit when there is a leakage current flowing to the earth or also known as earth fault. This is to minimize the risk of human life.
RCCBs usually can handle a fault or residual current of 1kA on their own if it is a fault to earth.
Wiring rules states that other devices should be operating together with RCCBs to provide protection. This can help improve the short circuit rating of RCCBs, thus for example a 1kA rated RCCB is able to operate at a fault level higher than 1kA.
*A Fault refers to an abnormal electric current. E.g a short circuit is a fault in which current exceed the normal load. It can also be refer to Residual current.
Residual Circuit Current Breaker with Overload protection, RCBO
This device is RCCB with a MCB, Miniature Circuit Breaker built in to it, also known as RCBO. It mainly protects against earth fault, overloads and short circuit currents. It also has the similar purpose of protecting lives like the RCD.

Ms Power Line Electric
01817104346
Dhaka Bangladesh.

RCD, Residual-Current Device or RCCB, Residual Circuit Current Breaker. It is an electrical wiring device whose function is to disconnect the circuit when it detects currents leaking to the earth wire. It also gives protection against electric shock or electrocution caused by direct contacts.