New buikd

[philipb]

Hi guys,
Got a new build to do in a couple of months time,not done one for a few years so i will be
brushing up on new build regs ect,but i could do with a bit of advise on the size and type of
board to use.Its a very large house with ground source heating so i will need a large consumer
unit or dis board.I had a look at a house next door and the board had 30 breakers in it in 3 rows of 10.
My question is what is the best way of doing this?one large box or a number of smaller ones,and what
type do you recomend for user friendlyness and cost.?Thanks.

 

[Paul.M]

How big is this big house? Just for the inconvenience of walking from the west wing to the east wing I would be going down the multiple board route depending on cost.

 

[Knobhead]

Out of interest is this a 3Ph supply. I assume with the heat pump it will be.

 

[philipb]

Yes sorry 3 phase supply,the house is approx 120 square meters on ground floor
and 110 meters upstairs,ground source heating from 3 bore holes summer house,and extensive lighting
and multi room multimedia,also zoned underfloor heating down and upstairs.

 

[Guest123]

The ground source will typically need a 60A single phase supply or less if 3P.

As said how big is big??? is it DB per floor kinda big???

 

[High Tower]

I did a really big re wire on a development of a massive house for a Asian family, so 7x 10mm shower supply's and a total if about 70 circuits, client diddnt want boards dotted around everywhere so we used 3x Crabtree double decker boards with the main switches changed out for RCD's, so 6x rcd, each board connected to a phase of the newly installed 3ph supply, worked well for us, or the tidiest but most expensive option is 1x 16 way 3ph hager invictus board with the glass door!, looks the dogs danglies but by the time you have stuffed it with at least 40 rcbo at £20 ish a piece it's a expensive way of doing it

 

[philipb]

That is a big house!no its not that big,the ground source guy has asked
for a five way bourd for the pump and controls,single phase for the pump.
I am thinking of a number off small boards say one for downstairs,one for upstairs,
one for kitchen,and one for summer house.anybody see any problem with that?
and one main switch for the whole thing.

 

[Engineer54]

OH My God!! Sounds like a well thought out installation ...CU's everywhere!! Marvelous!!!

 

[Marvo]

Yes sorry 3 phase supply,the house is approx 120 square meters on ground floor
and 110 meters upstairs,

It's not that big, 230 square meters is above average but it wouldn't warrant multiple DB's unless you particularly want to go that route.

 

[Engineer54]

It's not that big, 230 square meters is above average but it wouldn't warrant multiple DB's unless you particularly want to go that route.

230 Square metres isn't big at all, a largish 3 bedroom house or a pretty standard 4 bed roomed house. Certainly not big enough to go plonking CU's around everywhere!! The only one mentioned, that would warrant it's own CU is the summerhouse....

 

[Marvo]

On a few of the very expensive residential installs we've installed a DB in the basement or in a plant room for the air-con, swimming pool and associated heat pump, Jacuzzi, water features, garage climate control and extensive external lighting. This enabled all the SWA cabling and triple pole breakers to be contained in a commercial DB enclosure and the house CU to be kept to a sensible size. As E54 said the summerhouse and any other separate outbuildings may warrant a CU of their own.

 

[DNS1]

Isn't it a bad idea to have the house circuits split over phases?

I'm curious as I was previously a sound engineer. Running kit off 2 phases in the same place was seen as a big no-no...

 

[Marvo]

Isn't it a bad idea to have the house circuits split over phases?

I'm curious as I was previously a sound engineer. Running kit off 2 phases in the same place was seen as a big no-no...

It's common practice here if the incoming supply is 3 phase. If you run all the sockets on one phase, lights on another and stove and heating on the third then you can't balance the load.

 

[philipb]

As i understand from my commercial days we had to make sure there wasn't two phases hense
415volts in close proximity to each other.Thanks for all your comments,food for thought.
One of the reasons i am thinking of a few boards is cost of cable as the house is long and thin
and the plant room is right at one end.So cable runs would be long,thought it would save time and money to say run a main upstairs to a consumer unit and feed everything from there.

 

[High Tower]

Any 3ph installation be it domestic or commercial WILL. Have 400V at some point of the installation, it's inevitable, all you can do is minimise exposure to ordinary or instructed persons to the potential of 400V where as in a large domestic situation I can guarantee that you will have 400v between cables in places like the landing floor. If you cannot negate the need to have 400v at outlets then it needs a warning label.