tripping RCD and bonding question

[cashnotakite]

wondered if anyone can help me out with this;

I've recently changed a very old consumer unit over to a new split load 17th edition version.
The premises is a small bungalow with just one lighting circuit.
When i re-energised the board this particular lighting circuit kept tripping out the rcd. It has to go on the rcd side because it incorporates the bathroom.
With the old fuse board it wasnt detecting any fault so I guess this must be a N/E fault somewhere. I went round to check for any blown lightbulbs but no joy.
Anyone identify a possible fault with this?

Also the main gas and water are bonded and I am wondering do I have to supplementary bond anywhere? I have checked in OSG and am still not sure. There are no existing bonding cables other than the main gas and water bond.

Many Thanks!

 

[telectrix]

only solution is IR testing the circuit. break circuit at each fitting and trace fault. supplementary bonding is required on any exraneous metal parts that may introduce an earth potential. i.m a bit concerned with your new CU. you say it's 17th, but then you say " on the RCD side". a 17th board has 2 RCDs and under the 17th Edition, virtually all circuits must be RCD protected.

 

[malcolmsanford]

Well apart from a N-E fault it could be

Neutral connected onto the wrong bar
Low insualtion resistance on cables if they are old
Reverserved polarity somewhere ie N/E L/N
Faulty RCD
Though unlikely in a bungalow with just a single lighting circuit but don't rule out a borroewd neutral somewhere
Outside lights with dampness

As for the supplementary bonding regulation 701.415.2 covers that.

 

[ezzzekiel]

i.m a bit concerned with your new CU. you say it's 17th, but then you say " on the RCD side". a 17th board has 2 RCDs and under the 17th Edition, virtually all circuits must be RCD protected.

agree with telectric, are you partp registered and qualified?

 

[kmcgold]

depends on how the circuits are installed and type of circuit
you can get 17th boards with 2 rcd and a non rcd side.

 

[cashnotakite]

thanks for your feedback guys. its a wylex 17th board with 2 rcd sides and a non rcd side. when they cahanged the supp. bonding regs it left me bewildered on when you have to supp bond and when you dont.

agree with telectric, are you partp registered and qualified?

whats part P?

 

[ezzzekiel]

you are talking about a high integrity board, we are talking about

It has to go on the rcd side because it incorporates the bathroom.
Also the main gas and water are bonded and I am wondering do I have to supplementary bond anywhere?

providing all main bonds are in place, rcd protects all circuits in location and disco times are met then no supp bonding required.

have you tried swapping lights to other rcd or fitting rcbo on unprotected side?

 

[telectrix]

part pee is a little known building regulation that says you can't do this type of work unless you shell out oodles of cash to a scam provider every year and prove your competence to them. there is NICYUK, Elecsa, Napit, BSI. but if you are a registered plumber, you can do what you want, who cares.

 

[kmcgold]

17th board with 2 rcd sides and a non rcd side the one i was talk about is not high integrity board but you can get them.

 

[ezzzekiel]

can you expand on this? a fuse board with two rcd sides and unprotected side

http://www.tlc-direct.co.uk/Products/WYNHRS10SSLHI.html

 

[i=p/u]

your right telectrix, it sounds like a joke, it isss

 

[kmcgold]

http://www.denmans.co.uk/downloads_public/17th_mk.pdf

 

[B6 7BU]

whats part P?

Take a look at this


[video=youtube;GvNjg8sw1O0]http://www.youtube.com/watch?v=GvNjg8sw1O0[/video]

 

[cashnotakite]

have you tried swapping lights to other rcd or fitting rcbo on unprotected side?

is there any reason why putting it on a RCBO on the unprotected side would rectify the problem?

 

[ezzzekiel]

because if it has to go on the rcd side, then fitting an rcbo will still give the required protection but remove it from the rcd side. If there is a fault on the lighting circuit and then the other rcd (if there is one?) or the rcbo will trip anyway but the fault wont take out the rest of the circuits untill resolved.