The Tamil Nadu Electricity Regulatory Commission (TNERC) has recently added a safety regulation to the Tamil Nadu Electricity Distribution Code. It calls for erecting a residual current-operated device (RCD) in every consumer’s electrical installation to avert accidents. RCD embraces all types of residual current circuit breaker (RCCB).
RCD not exceeding 30 milliampere (mA) shall be provided for protection against electric shock in all consumer installations. For large installations with 10 kilo watt and above, RCD with 300 mA shall be provided for protection against fire and electric shock, according to the gazette notification.
When a person comes into contact with a piece of equipment having leakage of current exceeding 30 mA, he will be electrocuted if such an intensity of current passes through his body for a few seconds, said A.S. Kandasamy, former Chief Engineer, TNEB, and Member, State Advisory Committee, TNERC. He said the PVC cables in an electrical installation can sometimes split, crack, or even heat up at tension points, resulting in the leakage of current.
“If the leakage goes beyond 300 mA, there is an almost instant spark that can ignite any flammable object nearby,” Mr. Kandasamy said. He pointed out that fatal accidents and ignition of fire due to leakage could not be prevented by rewireable fuses and miniature circuit breakers (MCBs), which are intended to protect an electrical circuit/equipment from excess current due to a short-circuit and overloading.
RCD can be installed for all consumer service connections at the point of commencement of supply. “Electrical accident-free premises are possible through RCD. While people are spending lakhs on constructing their houses, many are not coming forward to install the life-saving device by spending ₹2,000 more owing to lack of knowledge...,” Mr. Kandasamy said.
