RCCB (Residual Current Circuit Breaker)
What is RCCB ?
RCCB is the safest device to detect and trip against electrical leakage currents, thus ensuring protection against electric shock caused by indirect contacts. It must be used in series with an MCB or fuse which protects them from the potentially damaging thermal and dynamic stresses of any over currents. They also act as the main disconnecting switches upstream of any derived MCBs.
A human being is able to sustain an electric shock to the extent of 30mA. While up to 10mA may just evoke a prickling sensation. A place where the floor is likely to be wet, protection against earth leakage current must be provided by a RCCB of sensitivity not exceeding 10mA.
10mA onwards may lead to muscular contraction, further leading to a respiratory paralysis at around 30mA. For an installation where hand-held equipment or appliance, protection against earth leakage current must be provided by a RCCB of sensitivity not exceeding 30mA.
For overall wiring (single phase/three phase) protection against earth leakage must be provided by a RCCB of sensitivity not exceeding 100mA.