New light issues

[djwestie]

After changing a few Plug sockets for Dbl's & changing a few old ceiling roses, i though i would buy a new IP44 Rated light for my bathroom ( to replace the bare bulb lampholder that was there).

SO purchased to new light (instructions were rubbish). After working out what wire was my Switch live ( it wasn't marked) I ran that into the Live on my light, 2 x N into light & 3 x Earths(using tails so the joins were above the light fitting in the ceiling).

That left 3 x Live loops which i ran into a choc/box. Turned on all working fine, Then a bout 3 hrs after i finished the main trip switch tripped(not the MCB for the light circuit). I removed the MCB from the lighting circuit & the switch still tripped a few hours later.

I think the issue is with the Switch live(might of been pinched/come loose), my reasoning is after pulling the MCB for the lighting circuit the main breaker stilled tripped (which leads me to believe it's not a problem with the Loop because there wouldn't of been any current running though them. But the Switch live (from my understanding has a consent current).

Would this be the 1st place to start my problem solving??

Any advise welcome.

 

[Risteard]

No. It's clear you don't know what you are doing. Got an Electrician.

 

[djwestie]

No. It's clear you don't know what you are doing. Got an Electrician.

Thank you for your prompt reply

 

[bernardgreen]

After changing a few Plug sockets for Dbl's & changing a few old ceiling roses

after pulling the MCB for the lighting circuit the main breaker stilled tripped

Could the fault be on one of the sockets you changed ?

There is permanent live voltage on the looped in Live . There is live voltage on the Switched Live when the switch is ON

As previously advised, get a electrician who is able to fault find. not one who only installs cable and accessories and lacks fault finding skills.

 

[djwestie]

After changing a few Plug sockets for Dbl's & changing a few old ceiling roses

after pulling the MCB for the lighting circuit the main breaker stilled tripped

Could the fault be on one of the sockets you changed ?

There is permanent live voltage on the looped in Live . There is live voltage on the Switched Live when the switch is ON

As previously advised, get a electrician who is able to fault find. not one who only installs cable and accessories and lacks fault finding skills.

I did use a socket tester on the new sockets which showed there wasn't any issues with them, but I will dbl check the wiring to them.

 

[djwestie]

I fitted the same light in my (separate toilet) 2 wks ago with out any issues, which is a little frustrating. The only differences with this one is the Earth, on the toilet light i used the earth from the switch & joined the others together, on this one it wasn't clear to me which was the earth from the switch so ran them all into a choc-box & ran a single wire to the earth on the light.

 

[ericmark]

I can only guess. But for what it is worth here is my guess, some where you have got a neutral connected to earth, the MCB does not switch neutral so a neutral to earth fault is not removed by switching or removing a MCB. The current travelling from neutral to earth varies with the voltage difference between neutral and earth, which in turn varies with the load.

 

[djwestie]

I can only guess. But for what it is worth here is my guess, some where you have got a neutral connected to earth, the MCB does not switch neutral so a neutral to earth fault is not removed by switching or removing a MCB. The current travelling from neutral to earth varies with the voltage difference between neutral and earth, which in turn varies with the load.

Thank you. Ericmark. I will dbl check ALL the connections. I was as careful as i could be trying to fit all the choc-box & wires into the recess above the fitting, If one had worked loose ( my best outcome) i should be able to fix it. If not then try to find a electrician Who

As previously advised, get a electrician who is able to fault find. not one who only installs cable and accessories and lacks fault finding skills.

I really appreciate people taking time out of there day to try & help me. If you ever have issues with large dia Drainage i'm your man.

 

[securespark]

Could be that you have pinched/ trapped/ shorted something together, causing the RCD to pop off.

Kill the supply, drop the fitting, look for a fault and then see it still trips the RCD while it is not screwed up.

 

[djwestie]

Could be that you have pinched/ trapped/ shorted something together, causing the RCD to pop off.

Kill the supply, drop the fitting, look for a fault and then see it still trips the RCD while it is not screwed up.

Hopefully Securespark this is my problem. I will why i'm at it make to hole above to fitting larger so it all fit's in without to much trouble.

 

[securespark]

Make a small hole into the ceiling that will be covered by the fitting, joint all the cables in a chocbox then push it up into the void.

http://www.screwfix.com/p/chocbox/5...5vePElz9XlHjE6EKeXe82NMHV6MtgTIJ2caAjZi8P8HAQ

 

[deadshort]

Hi, did you do all this work at the same time ? I.E. sockets and lights. If so, your light may be a red
herring.

Regards,

DS

 

[djwestie]

Hi, did you do all this work at the same time ? I.E. sockets and lights. If so, your light may be a red
herring.

Regards,

DS

Deadshort I changed the sockets in the morning & then did the light in the afternoon. After checking the light i will dbl check the sockets(even though i need use a socket tester) to make sure there isn't any exposed wires.

Thank you for all your help i am grateful.

 

[ericmark]

There are many socket testers, the EZ150

does a reasonable job, but the BZ101

is really next to useless at high lighting faults, the test kit like this

would high light most faults.

In the main insulation is tested using 500 volt, continuity is tested using at least 250 mA and loop impedance tester uses around 15 mA so as not to trip a RCD and the RCD tester measures time as well as current so can tell you how many mS it took to trip. These all cost money and some times it is simply not worth doing DIY as the test gear is so expensive.

The earth neutral fault can be really hard to find without test equipment. The example I quote is the bit of toast stuck in a toaster causing the RCD to trip when the kettle is used. First impression is the kettle not the toaster is faulty. But kettle uses more power than a toaster so it causes the earth and neutral to have a larger difference in their voltage so it reaches the tripping point.