help please rcd tripping

[tvbors]

right i have been trying to get to the bottom of why my cousins rcd keeps tripping , i have narrowed it down to one of the nuetrals connected on the rcd side of his board.
The board is a mess and mcbs are marked wrong i think that the nuetral is from a ring main, with the power off to the board when i connect this nuetral it still trips the rcd

My question is can i leave the nuetral disconnected and just make it a radial circuit (and does that mean i have to disconnect the corresponding live from the board too ,which wont be easy to trace)

my electrical knowledge is minimum
cheers tvbors

 

[burntwire]

You more than likely have the ring main neutrals mixed up any time you plug some thing in is it tripping ? but not tripping with nothing plugged in ?

 

[tvbors]

even with the power to the cu switched off and with all the wires connected when i put on the main switch at cu it trips rcd

but with the offending nuetral removed from the nuetral bar it dosnt trip the rcd (power to cu on or off)

 

[burntwire]

Yes it will if anything is plugged in, what you need to do is identify the neutrals, if you have one neutral on the wrong side of the neutral bar, there may be one the other way round, you musnt just disconnect the neutral, it has to be connected which is why its there,

When checking the ring main neutrals they must have continuity between both these 2 must go on the rcd side of the neutral

Has your cousin had any work done recently or has this been an on going problem ?

 

[tvbors]

his house and wiring is quite old, he did have guys in that wired all his kitchen sockets up onto the cooker mcb

every plug in the house was unplugged

but it is not possible for me to see physically which nuetrals and lives are from the same circuits as they dont come from twin and earth (or if the do the sheath is removed from before it enters cu)

if i dont connect the neutral would that not just make it a radial?

 

[burntwire]

No because you may not be disconnecting the ring main neutral, it may simply be on the wrong neutral bar , does it trip if connected to the other side,

It sounds like they may have mixed up neutrals while testing,

The best thing you could do is get a proper electrician in who will be able to test and trace the cable and make sure no ones drilled through a cable etc etc when fitting the kitchen.

 

[burntwire]

The kitchen sockets shouldnt be on the cooker mcb do you have any photos of inside the board ?

 

[tvbors]

i will take photos later or tommorow and post them up

the guys that did the kitchen werent electricians they were joiners i think and they refitted everything , the kitchen sockets are definitely on the cooker mcb probably spurred from the cooker connection unit

i will try the nuetral on the other side of the board (non rcd)

 

[burntwire]

You cant just creat a radial like that, the chances are that your ring main covers an area larger than it really should, and a radial covers a smaller area, it may be possible to split the ring in half , remove the link and create 2 radials however that neutral would still need to be fitted, the mcbs would need changing to a 20 amp and an extra one fitted and the circuits will need testing, it is obviously hard to say with out looking at your house this work will also need to be done by a part p registered electrician

 

[burntwire]

the work in your kitchen should have been done by a part p qualified electrician, you should have test certificates, confirmation from their governing body that this work has been done and registered, (or they should have informed the building inspector if not part - p), you should make them come back with a qualified electrician and sort out their work,

 

[tvbors]

when the nuetral is moved to the non rcd side its fine

 

[electronicsuk]

when the nuetral is moved to the non rcd side its fine

Do you think that might be because the circuit is no longer protected by the RCD?

Although it's possible, as already suggested, that the circuit may have had live connected on the non-RCD side and neutral on the RCD, surely you would have noticed this before now? Has it only started happening since the kitchen was fitted?

Even though you think you've fixed the problem, there could be other things going on that you're not aware of. For example, what happens if you have a broken ring circuit with a N-E fault on one leg? The live could still be from the RCD side of the board, but it might just so happen that there are no loads on that section of the ring (now a radial).

Admittedly it's a longshot, but it's just one example of many possible faults. You would be far better off getting in an electrician with the appropriate test equipment, for peace of mind if nothing else.