So just now I was adding an extra light over my day bed it's a vintage 60 watt bulb looks like an old radio valve it even has the little glass pip on top. Anyhow as I was wiring it up two whiskas of wire touched there was barely any sound but it popped the 5 amp fuse in the plug adaptor and tripped 16 amp MCB how is this even possible even under partial short circuit conditions surely a 5 amp fuse should clear before a 16 amp MCB?
In our study/home office there are two extremely well ventilated ceiling fittings, each with 4 GU10 lamps. For some reason (I am now suspecting either over-voltage and spikes) when tungsten GU10s, they never lasted that long, but inevitably when one failed, usually at switch on, it would take the 6A MCB with it. Seems to suggest that as the filament failed it arced across, but is that the reason? From Tungsten went to compact GU10 florescents and now LEDs. But the LEDs do not have the expected life, nor did the compact florescents. Their electronics should have handled the over-voltage (we are not far from the sub-station, whilst within limits, generally around 243 volts. So perhaps spikes?
Anyway, my experience is that when a lamp fails, it causes a current surge such as to blow the MCB. In your case, I am assuming that the MCB was not supplying anything else?
In our study/home office there are two extremely well ventilated ceiling fittings, each with 4 GU10 lamps. For some reason (I am now suspecting either over-voltage and spikes) when tungsten GU10s, they never lasted that long, but inevitably when one failed, usually at switch on, it would take the 6A MCB with it. Seems to suggest that as the filament failed it arced across, but is that the reason? From Tungsten went to compact GU10 florescents and now LEDs. But the LEDs do not have the expected life, nor did the compact florescents. Their electronics should have handled the over-voltage (we are not far from the sub-station, whilst within limits, generally around 243 volts. So perhaps spikes?
Anyway, my experience is that when a lamp fails, it causes a current surge such as to blow the MCB. In your case, I am assuming that the MCB was not supplying anything else?
