Outside lights tripping breaker

14 Nov 2005
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United Kingdom
I've just moved in to a new house and the garden is lit by two 500w halogen lights wired to the same switch. The problem I have is that occasionally the breaker will trip when I turn the lights on. The outside lights are on their own circuit with a 6amp breaker in the board. Is the breaker the right size for this or is switching what is in effect 1000w too much :?: Thank you in advance for any help anyone can give me so that I can venture out to the garage without having to keep resetting the breaker on a regular basis.
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You could try and replace the lamps with 300W ones.This would be the simplist solution rather than getting involved with changing breakers, checking cable size and EFLI.This would also reduce your running costs to have the lights on.If after this you still have a problem then you are looking at possibly a faulty breaker or an intermittent fault on the wiring to the lights - both best checked by an electrician
have you checked the lights for any moisture/water? does it happen after its been raining a lot? its not protected by an rcd is it?
Is it the 6-amp breaker that trips? Or is it the RCD?

Would it be convenient to switch them individually with separate switches? (I am thinking of the combined switch-on current surge here)

Changing to 300W tubes sounds like a good fix (they are the same size as the 500W)
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Thank you for the replies. I have looked today and the lights and connections are bone dry. Although there is an RCD in the board the lights are on the non RCD side. It is the 6A breaker that trips and not the RCD. Is going down to 300w lamps the only option or is there another solution as I would like to keep the light level the same if possible as it's a very big garden. do you think that the two lights on a 6A breaker are enough to trip it out. Would changing to a bigger breaker be a safe option.
You could change the breaker to a C, but as mentioned above it would need some calculations done - and without accurate measurement you have to make some estimates which are usually very inaccurate. So it is not really a DIY job. Can you see the make and model of your Consumer Unit and MCBs? Is it a B06?l

If, as I suspect, it is the switch-on surge that does it (I don't think I've got any load curves for halogens) then you could probably avoid it by putting each lamp on its own switch, slightly apart so that you can't turn them both on at the same instant. That way there will only be one surge at a time instead of two simultaneous ones.
It is a Wylex consumer unit and the breaker say's NB06 on it. I don't think it would be a straight forward job to put each light on it's own switch as it is wired from the switch to the first light and then from the first light to the second light. Would putting 300w bulb's in be the only practical option or is there another way so that I could keep them as 500w :?: thanks again for the help.
Some suggestions have been made.

You choose one.
B&Q were selling a lamp by GE last year, claiming 500w output but only 300w consumption. Bought one (it was about £5 though), and I dont notice any less brightness.

One more thing, putting the lights on 2 switches wouldn't stop people flicking them at the same time. For example in a shop with a 9-gang gridswitch for the lights, the staff will just run their hand down them to turn them all on at once. They aint gonna fanny about flicking each switch and waiting while the lights are lit.

The circuit should be designed for this. By spacing the switches by 10 metres, so the lights come on while you're walking to the next switch :LOL: ;) ONLY JOKING

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