What is Residual Circuit Breaker?
Residual Circuit Breaker (RCB)
What is Residual Circuit Breaker?
RCCB (Residual Current Circuit Breaker) falls under the category of a wide range of circuit breakers. As we know there are several types of miniature circuit breakers like MCCB which work on different operational principles and have different safety purposes.
Function: Residual Current Circuit Breaker is essentially a device which senses and disconnects any low voltage (unbalanced current) circuit whenever there is any fault.
Purpose: Residual Current Circuit Breaker basically is installed to prevent humans from shocks or death caused by shocks. It prevents accidents by disconnecting the main circuit within a fraction of seconds.
Working Principle of RSB
It has very simple working based on Kirchhoff’s Current Law i.e. the incoming current in a circuit must be equal to the outgoing current from that circuit. This circuit breaker is made such that whenever a fault occurs the current balance of line and neutral did not match (imbalance occurs, as the fault current finds another earthing path of current).
Advantages of Residual Circuit Breakers
- Provides protection against earth fault as well as any leakage current.
- Automatically disconnects the circuit when the rated sensitivity is exceeded.
- Offers possibility of dual termination both for cable and busbar connections.
- Offers protection against voltage fluctuation as it includes a filtering device that guards against transient voltage levels.
Limitations of RCCB
While RCCB has many advantages, it has some limitations as well:
- RCCB does not guarantee to operate if nonstandard waveforms are generated by loads. It is mainly because RCCB is designed to operate on normal supply waveforms.
- There might be some unwanted tripping of RCCB. It is mainly because whenever there are sudden changes in electrical load, there can be small current flow to earth especially in old appliances.
- RCCB does not protect from current overload. It has been designed to protect only when the live current and neutral current are different. However, a current overload cannot be detected.
Types of Residual Current Circuit Breaker
2 Pole: It is for a single phase line consisting of one live and one neutral wire slot in it. 4 Pole: It is designed for three phase lines consisting of 4 slots where three phase wires and a neutral wire can be connected.
Conclusion
Hence it provides a real time protection device for major circuits used commercially in industries and other high voltage commercial places where there is always a risk of shocks and accidental deaths due to it.