Keeps Tripping

[carl9254]

installed a PIR Outside light today, took supply from landing light to a junction box, live down to switch and back upto junction box as swith live, then switch live, neutral and earth out to light. The light did its test and seemed fine and the downstairs lights swithed on too. So went away happy, few hours later got a phone call back, the MCB had tripped, the guy came back to his house while dark, the outside light worked but as soon as he went in and switched landing light on it tripped the MCB and it wont reset, you just see a blue spark everytime you try to reset????

HELP???

 

[Guest123]

Hi.

Well the blue flash suggests a short circuit somewhere.

Could be a pinched conductor somewhere, best thing to do is re-check all your terminations and fixings etc.

P.S what is the loading on the circuit???

 

[carl9254]

Not much, 5 9w lights and the new 60w outside light, if I diconnect my new circuit from supply end should it reset??

 

[Dannyg83]

if u put landing light switch in off position it will probably reset

 

[Guest123]

You havn't taken line off upstairs and neutral off downstairs have you???

 

[lister]

Has it rained since you fitted it ?

 

[pushrod]

You havn't taken line off upstairs and neutral off downstairs have you???

that would trip an rcd, but would it trip an mcb? OP says it's an mcb that's tripping out.

reckon your first suggestion of a short and checking terminations, especially in the JB, is the most likely.

 

[kduck]

sounds like water in it to me too. It would trip the mcb.

 

[Guest123]

Just trying to throw some Q's in there.

 

[pushrod]

sounds like water in it to me too. It would trip the mcb.

would the outside light have come on in the first place? It was the internal switching that tripped the mcb.

 

[Dannyg83]

Short at landing light for me , nothing to do with water , he tried to switch on landing light and the mcb tripped first place i would check

 

[carl9254]

All switches are in off position and it still wont reset. Dont think its rained since. As soon as i switched it on the light did its test to detect whether daylight or not then it didnt come on till the guy came home at night, he went in his house and put landing light on and then it tripped. The landing light defo worked before i went home.

Thanks everyone.

 

[pushrod]

Will it reset when the power is off?

If it's a switch/push button type mcb i've known them to be quite finicky when resetting. The switch must be pushed firmly down before the button can be put in and then the switch can be reset.

 

[Yooj]

Hi Carl,

Was this that job you were talking about the other day in terms of ways of doing it, time it took you etc?

If so, how close were you to your time/materials estimate?

Don't worry about the fault-finding on this...happens to all of us at some point...It is likely to be a simple fault which you will find straight away.

Yooj

 

[beanzntoast]

IMO nothing to do with water as this would also trip the RCD,As lenny said i would start from the begining re-check all your connections/terminations especially in you juction box could be just something as simple as that

 

[carl9254]

Yea this is the job, it all went quite well really till the phone call, even did a bit of plastering. took about 5hrs ish which im happy about at min.

And havent tried turning all power off, yet, ill investigate tomoz, first thing ill do is check jb, then landing rose then new light, bit dissapointed but i suppose its all learning

Thanks.

 

[a.e.s]

Hi carl, did you go back to that job today? if so how did you get on, did you get it sorted??

 

[SirKit Breaker]

Is the new light that you have fitted good quality, has the internal sensor failed?, i would disconnect your new install and put everything back as you found it, then you will know if its what you have done or not.

Good luck.

 

[empress]

Is it the MCB or RCD thats tripping?
iF its the rcd / new board and old wiring could be a shared neutral , 2 way landing lights could be the prob.

 

[Christech]

Check Switched Live & N connections to PIR they are unlike lights polarity conscious.You maybe dead shorting.

 

[carl9254]

Fixed this yesterday. Took switch off and tried resetting mcb and it reset, put another switch on and fine, bit strange but guess they are faulty sometimes

 

[beanzntoast]

That is a strange one how a faulty switch can trip an MCB when theres only live's going to it,Never heard of that 1 before.you learn something new everyday

 

[amp]

Carl i would go back and check the cables in the light switch you may have crushed the live with the plate screw and now have an exposed live conductor where it was crushed this can be very easily missed. This will blow an mcb especially ir there is no RCD

 

[nrbspark]

I agree you should look for a damaged live in the switch, this was probably enhanced by the plastering work you carried out with the moisture in the plaster causing the short from permanent live in switch to the back box.

Hope this helps.