Thursday, 4 August 2016



RCCB refers to Residual Current Circuit Breaker which is a rival to the ELCB(Earth Leakage Circuit Breaker). As both the circuit breaker works for the same cause but the difference is RCCB connectivity is different also it gives better protection over ELCB.

ELCB is a voltage operated device which has Line,Neutral, and Earth Connections detects potential in the earth when the voltage is non-zero and indicates that there should be a leakage current in the earth and it protects by tripping.The ELCB can protect from earth fault only  and doesn't provide protection from overload and short circuit so better opt for RCCB than ELCB.

Meanwhile, RCCB which has Line and Neutral connections and the working is when there is a difference in current level from Line to neutral indicates a fault or earth leakage and it trips.As line current always equal to the neutral current which flows back in neutral conductor any difference in current means that somewhere earth fault occurs so the RCCB will get tripped.

The RCCB doesn't require earth connection so that even it can provide shock or fault protection to the device which does not have the earth of its own.

The Tripping of the RCCB is within 30milliSeconds of the earth fault.
The widely used RCCB rating is 30mA and 100mA.
The Human body can withstand up to 30mA.

Like ELCB, RCCB doesn't protect from the following,

1.Overload(Due to huge current even undetected).
2.Nuisance Tripping(Due to sudden changes in electrical load like switching Airconditioner or Motor etc...)
3.Non-Standard Waveforms(Not guaranteed for the operation by other than nominal waveforms like from halfwave rectifiers).
4.Short Circuits(Due to Line-Neutral Schock).