British General Distribution Board

[paul77]

I've just put in a 10 way BG board into my house in preparation for my Part P competent person assessment.

After using all 10 ways I have run out of space on earth terminals, because as you all know to comply with wirring regs the two ring circuits will take up four connections.

I phoned BG tec support and was told that they don't offer an earth bar extension kit and apparently I was the first person to ask for one!! (  find that hard to beileve).

I don't want to fit an external earth bar just for the ring main and wire a 16mm cable back into the DB as it will look S**t.

I can free up the 2 of the 3 E terminals by a separate earth block in the meter cupboard and earth the SWA armour at the garage end.

This will then stuff up the earth numbering which again is another no no under the regs.

Has anyone any other Ideas???

Appart from changing the DB to a 13 or 16 way.

Will a extension kit from another manufacture fit??,

Cheers

 

[Andy™]

 because as you all know to comply with wirring regs the two ring circuits will take up four connections.

as you should know, you dont need 4 terminals for 2 ring circuits to comply.

both go into the same terminal, same as L & N into MCB / neutral block. of if you have high integrity earthing, then you can put a conductor from circuit 1&2 in terminal 1, and the other conductor from circuit 1&2 into terminal 2...

 

[Technician]

Just going on from Andy, are you sure that the ring final

circuits you have installed need high integrity earthing?

 

[SLIPSHOD & SLAPDASH]

As above. You dont generally need this in a domestic situation.

Also, off topic  a bit but as this is for your Part P assessment i believe from others you will need to have this signed off by the local building control . Maybe other members can comment ?

 

[Technician]

From an earlier post by Bulmer.

New boards are still notifiable.

http://www.elecsa.co...iable-work.aspx

 

[SPECIAL LOCATION]

I phoned BG tec support and was told that they don't offer an earth bar extension kit and apparently I was the first person to ask for one!! (  find that hard to beileve).

:shakehead

I don't find it hard to beleive....

But it is a bit worrying that anyone is contemplating having any sort of assesment...

OR..

doing electrical work without getting a good knowledge of the wiring regs and building regs first!.

I always though the competent persons schemes were there to asses sound knowledge of BS7671 & all relevant building regs Approved documents...

Not just have a look at some practical work...

I may be wrong of course...

Perhaps you do have a lot of high leakage currents from your appliances in your home with the risk of high CPC currents...

But if I was a betting man I would doubt it very much....

You may want to have another read of 543.7  starting on page 165...

(possibly missed out on a short course!! )

:coat

 

[Theorysparky]

If it is for your assessment don't bother notifying it ,, do it when you have finish the work being carried out

ie the extra socket in the garage you have not had time to do ????

 

[Andy™]

Just going on from Andy, are you sure that the ring final

circuits you have installed need high integrity earthing?

only at the board. sockets probably have both earths in the same terminal

 

[Blue Duck]

Can you re-route/extend the W/G bonding so you can use an external main earth terminal??? then freeing up 2 spaces?

Added a radial cct to a wylex skeleton in a mantel today... some nice person had stuffed loads of unstripped 10mm in the back so it was a bu**er getting the parallel earth in but got there in the end where there is a will there is a way...

I wouldn't notify LABC as it will cost you on top of your assessment...also stay away from screwfix until you find what suits you rather than whats on special.

 

[Andy™]

You can get em with twin terminals in sockets for HI earthing - Got some for a mate of mine last year

yes, but the sockets already fitted probably dont have them, or if they do, both earths will be in the same terminal

 

[Evans Electric]

Just stick them in the same earth terminal .   If it worries the assessor let him take it up with whoever .    Its domestic , just do it . 

 

[paul77]

Thanks for the advice

No I don't need to have Hi earthing and thanks for pointing out 5.3.7

I think figure 7.5.3 page 79 in the onsite guide through me. I should have read 7.5.3. :facepalm:

I'll chuck them into the same terminal.

As far as the assessment stuff goes I'm I've got 2365 level 2&3 2394/5 practical online exam just waitng on the results of the written paper.

Got lots of minor works, my consumer unit is the major one.

So once I pull it all together I can book the assessment.

The only reason I went with BG is because they are part of the Nexus group.

Nexus are big in the Data installation world with a good reputation.

A good mate of mine has been using them for 10 years, so I thought I would give them a try.

 

[Evans Electric]

Hope he's not as keen as the last one a  fellow ELECSA' ite  had .  Apparently had him carry out every test known to mankind ....obviously thinks he,s learned nothing over the last 40 years  in the trade. :C

 

[paul77]

I hope not as well

I've a workshop at the bottom of the garden which is obversely on a TT system and therefore seprate to the DNO earthing.

so it looks like I'll be watering the plant next to the earth rod or praying for rain just before he comes around to try and get under the magic Ze of 21ohms.

Plus I better brush up on the earth rod impedance test.

 

[Andy™]

I hope not as well

I've a workshop at the bottom of the garden which is obversely on a TT system and therefore seprate to the DNO earthing.

so it looks like I'll be watering the plant next to the earth rod or praying for rain just before he comes around to try and get under the magic Ze of 21ohms.

Plus I better brush up on the earth rod impedance test.

and you best brush up on rod resistances too. 7671 does not state 21 ohms...

 

[paul77]

Max Ze of a TT system anything over and you need a RCD.

But as you need an RCD on a TT system anyway it is a bit irrelevant but if he wants to get picky anything over 21 and protection is down to the RCD.

Some people don't like it as protection is lost if the RCD fails.

Introduction of the onsite guide page 11

542.24

 

[Andy™]

Max Ze of a TT system anything over and you need a RCD.

But as you need an RCD on a TT system anyway it is a bit irrelevant but if he wants to get picky anything over 21 and protection is down to the RCD.

Some people don't like it as protection is lost if the RCD fails.

Introduction of the onsite guide page 11

542.24

7671 makes no reference to TT & 21 ohms....

and 542.24 has nothing to do with rod resistance either

 

[M107]

Paul who are you going with for the Assessment? If it's NICEIC the assessor for our area is spot on.

 

[batty]

Well if they pass you with the knowledge you have this will explain why the electrical trade is in the state it is. I am sorry but this is basic stuff surely you need to know the basics before going out into the big wide world and earning a living doing electrics.

 

[steptoe]

I hope not as well

I've a workshop at the bottom of the garden which is obversely on a TT system and therefore seprate to the DNO earthing.

so it looks like I'll be watering the plant next to the earth rod or praying for rain just before he comes around to try and get under the magic Ze of 21ohms.

Plus I better brush up on the earth rod impedance test.

21 ohms on a TT is pretty rare, Ive often had problems getting under 200 !!!!

I wouldnt worry too much about the rod impedance,

I'd be more concerned with its resistance,

does your tester measure rod resistance?

that could be interesting if the assessor asks for that test?????????