hi everyone
went to a call today reguarding a tripped rcd and loss of power to garage. When i arrived the the rcd had been reset and all mcb's were on and all circuits working normally. one 16amp Mcb was off and no power to garage. She said her son had reset rcd but thought the problem was with the 16amp Mcb. Nothing strange there.
when entering the garage i found the wiring to be in a terrible state with sockets and lights all on the same circuit some lights hard wired thru junction boxes and some plugged in to sockets by flex. All in poor condition. there was also an old freezer, poor condition that i initially thought might have a leakage problem that was causing the rcd to trip. But that was now beeing run via an exstension lead to the kitchen ring main and had caused no tripping.
i unplugged the freezer and as many of the lights i could find from the circuit. i expected the 16 A mcb to not reset as i expected the cause of the trip may be a E to L fault but to my surprise it did reset and the rcd held. i then plugged in the freezer and other lights and it continued to hold. then after about 6 mins the rcd and mcb tripped. i then carried out a basic IR test on the garage circuit and found L to E 0.00 ohms. E to N 0.00 and L to N 0.00 basically a short between all cables. Now the N to L reading could probably of been a connected load just strange that the rcd wouild reset at all let alone hold with the readings obtained. any thoughts as to why the rcd reset ?
went to a call today reguarding a tripped rcd and loss of power to garage. When i arrived the the rcd had been reset and all mcb's were on and all circuits working normally. one 16amp Mcb was off and no power to garage. She said her son had reset rcd but thought the problem was with the 16amp Mcb. Nothing strange there.
when entering the garage i found the wiring to be in a terrible state with sockets and lights all on the same circuit some lights hard wired thru junction boxes and some plugged in to sockets by flex. All in poor condition. there was also an old freezer, poor condition that i initially thought might have a leakage problem that was causing the rcd to trip. But that was now beeing run via an exstension lead to the kitchen ring main and had caused no tripping.
i unplugged the freezer and as many of the lights i could find from the circuit. i expected the 16 A mcb to not reset as i expected the cause of the trip may be a E to L fault but to my surprise it did reset and the rcd held. i then plugged in the freezer and other lights and it continued to hold. then after about 6 mins the rcd and mcb tripped. i then carried out a basic IR test on the garage circuit and found L to E 0.00 ohms. E to N 0.00 and L to N 0.00 basically a short between all cables. Now the N to L reading could probably of been a connected load just strange that the rcd wouild reset at all let alone hold with the readings obtained. any thoughts as to why the rcd reset ?
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