Lighting Circuit Tripped....?

crosstownk

For no apparent reason, my downstairs light circuit tripped this evening. I was just walking through the hall and all went dark. I flicked the tripped switch back up and normal service resumed. I had a quick look and all the bulbs are working. It only happened once so maybe it's just one of those things. Anyone know why this would happen? I've 30 bulbs on this circuit (most are CFLs) and none would be in excess of 50W and obviously not all are on at the same time. When the switched tripped about half of them would have been on.

I also noticed that the central heating boiler is on the same circuit - is this normal practice?

DublinDilbert

30 is a large number of lights for one circuit, as the circuit should just cover one floor of your house.

Say they were 50w each (i know most of them are lower), 30 x 50w = 1500w, which is about 6.5A.

It would be best if the heating was on a separate MCB, if it was me i'd get it moved on to its own MCB (assuming space in the board), even just to help fault finding.

Do you have any outside lights on that circuit? These can drive up the load on the circuit too (could be 500w). Also water can get into these and cause intermittent problems like you mention.

I think i've mentioned it here before, one time i had a similar problem with a lighting circuit, it turned out that a slug had found its way into a junction box for the outside light. He was managing to blow the 10A fuse! The best thing of all was the fecker lived to tell the tale... :eek:

crosstownk

DublinDilbert wrote: »

30 is a large number of lights for one circuit, as the circuit should just cover one floor of your house.

Say they were 50w each (i know most of them are lower), 30 x 50w = 1500w, which is about 6.5A.

It would be best if the heating was on a separate MCB, if it was me i'd get it moved on to its own MCB (assuming space in the board), even just to help fault finding.

Do you have any outside lights on that circuit? These can drive up the load on the circuit too (could be 500w). Also water can get into these and cause intermittent problems like you mention.

I think i've mentioned it here before, one time i had a similar problem with a lighting circuit, it turned out that a slug had found its way into a junction box for the outside light. He was managing to blow the 10A fuse! The best thing of all was the fecker lived to tell the tale... :eek:

Thanks for that.

I did suspect the outside lights especially as there's been a bit of rain lately. I've 4 outside lights and all are CFLs. One 9W and 3 22W. Maybe moisture was to blame.

I just removed one of the ceiling lights in the kitchen and it's a 50W - I have 10 of these and they were on at the time. So that's the equivalent of 1 500W bulb.