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?
[snip] 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?
Indeed, we were in the same position with GU10's. My hypothesis is, that the low Zs value due to being close to the substation (it's just across the road) and the higher than normal voltage (240-245 here depending on time of day) causes the GU10 capsules to arc over internally, given their small size, the electrodes are closer together than in a typical GLS lamp. I caught the violet flare from one before the mcb tripped, which is what confirmed arcing as the cause for me. I replaced them with LEDs, never looked back.
[snip] 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?
Indeed, we were in the same position with GU10's. My hypothesis is, that the low Zs value due to being close to the substation (it's just across the road) and the higher than normal voltage (240-245 here depending on time of day) causes the GU10 capsules to arc over internally, given their small size, the electrodes are closer together than in a typical GLS lamp. I caught the violet flare from one before the mcb tripped, which is what confirmed arcing as the cause for me. I replaced them with LEDs, never looked back.
