More fused spur problems!

[Nocker]

Hi

Just installed two outdoor 2 pir lights on my boss house.

Ive spured off the downstairs ringmain 2.5 twin to the spur and 1.5 flex out to the light.

I was told that the right side of the double socket was not working after installing, the right hand side of the socket showed a slight burn mark on one of the plug entrances.

I checked both sides of the socket with my socket and see and all wiring was ok. (i.e no reverse polarity)

Switched on mcb and spur, all ok. Goes outside to test load end of the cable with my normal fluke voltage tester. As soon as i test between phase and earth the RCD trips.

At my wits end as to what the problem may be. Any input would be helpful, cheers guys!

 

[timo1]

If the socket wasnt working then I can only think that there is a loose connection or the socket itself is faulty in which case I would try a new one. For an RCD to trip it must be detecting a fault which is introduced when you test. Bit of a long shot but I remember at college one of our tutors warned about some of the voltage testers we were using may trip the rcd as they pull a certain amount of current to operate. Have you tried powering the light to see if it works? Id also double check the wiring in the FCU just in case, the smallest nick in cable can cause you all sorts of problems.

 

[Nocker]

Cheers timo

Socket was all working as per socket tester. The tester i used on the outside 1.5 cable was only a fluke T100 voltage and continuity tester. When testing between phase and earth to try and indicate 230v after switching spur on the rcd tripped. I am going to reterminate all cable ends and replace socket with a new one and take it from there. Any additional info from anyone else will be much appreciated to take onboard on my return.

 

[rugbynick]

why are these not on lighting circuit?

 

[timo1]

Cheers timo

Socket was all working as per socket tester. The tester i used on the outside 1.5 cable was only a fluke T100 voltage and continuity tester. When testing between phase and earth to try and indicate 230v after switching spur on the rcd tripped. I am going to reterminate all cable ends and replace socket with a new one and take it from there. Any additional info from anyone else will be much appreciated to take onboard on my return.

No problem mate, these things can be maddening its usually something really simple but you cant see it until you take a step back. Once you rule out the terminations and checked there has been no cable damage, I then look at the equipment - even brand new RCD's can develop a fault within an hour of being turned on. Its a good feeling when you find the fault though, even if like me you are generally on your own and have to celebrate by yourself lol.

 

[Guest123]

The fluke T100 series WILL trip an RCD if you test between L&E. If you test between L&N first for a second or 2 then test between L&E it wont.

It's all to do with the internal mechanics of the tester.


From the Fluke manual.....


During voltage test in systems equipped with RCD circuit breakers, a RCD switch can be tripped at a nominal residual current of 10mA or 30mA by measuring the voltage between L and PE

-> To avoid RCD tripping a test has to be carried out between L and N during approx 5s. Immediately afterwards, voltage testing between L and PE can be carried out without RCD tripping.

 

[polo1]

You beat me to it Lenny. When I first started using this fluke model I didn't read the instructions and wondered what I was doing wrong!:tounge_smile:

 

[Guest112]

lennys right "warm up" the tester line to neutral befor testing line to earth

 

[Mr.Ian]

If there's a sign of burning on the socket front then obviously it's the internal grips that grip the pins on the plug that are worn and not gripping causing sparking and overheating, your tester will say it's wired ok as it's not drawing any current. They might be nothing wrong with the wiring behind it's just a knackered socket. Both sockets in a double socket are supplied from the same terminal obviously so if one side doesn't work bin it.

 

[Nocker]

Guys thank you so so much.

Saved me the embarrasment of scratching my head whilst people are watching me. haha. (dont you just hate that feeling)

Again thanks a lot for everyones imput. Really appreciate it.

 

[Guest112]

ive had socket outlets before where one side worked and the other didnt, customer had cheek to blame me and after i explained how wrong she was "well it worked yesterday" that old chestnut lol needless to say next call i had for more work i was "too busy" lol

 

[Mr.Ian]

I see a lot of appliances that have been used in worn sockets, burn marks on the tips of the line or neutral pin and in some cases the insulation on the plug pins can melt due to the heat of the bad connection. Just imagine though that this can also happen on the earth pin creating a very very poor earth return. Worn sockets can be lethal.