Square D Distribution Board

[androiduk2002]

It might help to understand a few things and if i get it wrong some one will point it out in greater detail.

An average 3 bed home

3 circuits for socket outlets how this is done differs from electrician to electrician 1 for kitchen 1 for front 1 for back some do it 1 for kitchen 1 up 1 down.

For your size dwelling i would say no more 5 circuits but I could be wrong.

2 circuits for lighting using normal pendant fittings ,normally 1 up 1 down. For your property with out detailed plans/specifications I would not like to guess maybe one of the others would give a ball park figure.

1 cooker circuit

1 shower circuit per electric power shower.

maybe a circuit to garage if built on side of house.

so for an average 3 home 8 circuits in total , Im in a 3 bed maisonette and we only have 6 circuits so there is no hard and fast rule.

What I am trying to show is 30+ circuits does seem a bit over the top.

This is from my training eye as I said if i am totally wrong someone will point out the error of my ways.

 

[ProDave]

The only way the CU can cost that much is if he's having 30 circuits all on their own RCBO at

 

[a1]

Would it be possible to see a Photo of your house? Not to worry if not, but it would give a better picture to see it. (I know you have stated the size in square meters).

Just A Thought.

 

[confused]

I did eventually get a price for the work and then spent another couple of months getting a breakdown and agreeing the individual items. It was a painful process and no work was done whilst we sorted out the scope of works and a fixed price. That was for everything, except the distribution board and one or two smaller items. I have made it clear that any changes to the agreed price - including the distribution board - must be agreed in writing before any work can proceed.

It may be too late, but I have now got some control over the process. Unfortunately, it still remains a battle to get the advice that I need to make informed decisions and to have confidence in that advice. Hence, my seeking guidance from this forum.

Regarding the number of circuits, yes it does seem a lot. I have taken this at face value, but maybe I need to question it further.

 

[green-hornet]

Without us seeing the design it would be unfair to suggest that 30 circuits is more than you need, but very likely.

I always try to give the best advise I can to a client, I also give them options which helps them decide by cost what work they want to be done.

Without the input from your electrician we only have one side of the story, you could get him to sign up on this forum and air is view, then we can advise him of the options to help you save some money and more importantly get what you want and not what he has decided your having.

 

[NozSpark]

Or you could go for stacked CU's with a single isolator switch..

like this

www.flickr.com/photos/n-e-electrical/4584011073/

OK so the one you would want would have a few more circuits and wouldn't need the timer & contactor,, but it is quite do-able and doesn't cause any major problems with the regs... that one cost <

 

[jl-heating]

generally a ground source of that size 3 phase supply is usually the way to go .

i honestly think you need to get the design checked before throwing any more pennies at the build .

you say 50 amp on the start up, usually 3 immersions in the buffers for the 60 degree boosts, loats of load a single phase supply even with deviation will be well over .

do you have a detailed schedule for us to look at ie: circuits etc or at least a complete breakdown of proposed loads ie:

ground source ?

cooker ?

showers ?

lighting 2 maybe 3 circuits,

rings or radials ? 3 maybe 4 ?

smokes ?

garage ?

hot tub?

kitchen ring ?

omg i cant even think of 15 never mind 30 lol

seriously check the ground source we always ask for a 3 phase supply anything over 12KW.

also check out air source i think it has more advantages .... mitsubishi is the god of air sourse dont go cheap trianco .

 

[wozz]

tbh 30 circuits doesnt suprise me. modern heavily insulated home i prefer to put in lots of smaller circuits dont have to pull bigger cables round, less problems when one trips. For instance on new builds i generally put kitchen appliances on their own radials. Add to this the green features, plenty of lighting, garden lighting, gates, outbuildings the list is endless.

 

[jl-heating]

take ur point and generally a good idea...... but 30 ????? hehe

i have done 3 bed houses with 3 circuits lol.... oh joy .

 

[M107]

Send him away with a flea in his ear & advise he could (as Noz has pointed out) use a single phase conversion kit & use a 3 phase db...

Or

Use single phase MK with stacking kit....

Or use

single phase 32 way consumer unit.

All far cheaper than 2K

 

[matt.leung]

where and how did u find ur electricain? i think he is after ur money....

 

[kme]

There are a number of ways of looking at this:

1. Your electrician says you can`t have multiple boards; due to some reg?

Oops. Sorry, he`s wrong.

2. You need 30+ circuits - maybe; although unlikely. Even if all the first fix is in, there are ways & means of reducing the number of final circuits. If most of your lighting is LED, the load is fairly low, so no need to have masses of lighting circuits.

3. Has your architect, or yourself, specified high-integrity? If he`s fitting individual RCBos to 30 odd circuits, there goes lots of your money. I`d look at having smaller boards, with certain ccts on RCBo, and the rest segregated amongst a few RCDs.

4. I would agree 100% with JL reference the ground source. Lumping that on, as a single phase load, is ill-advised from my point of view.

KME

3.

 

[confused]

I have now finally spoken with my electrician, which has been useful. In summary:

Due to the amount of additional Circuits a single standard board is inadequate. At present there are 30 circuits - the additional 6 provide some additional spare ways for the future.

The maximum on a 17th Edition Type board is 34 outgoing, which he says will suffice, with some RCBOs for essential circuits and MCBs for externals. The house would be split into 3 sections and operations of an RCD would switch off 6 or 8 circuits at a time.

For a number of reasons, more related to lifestyle and convenience than the technical demands of the system, he would recommend that we design the system to switch off individual circuits rather than groups of 6 circuits at a time. This would involve the use of RCBOs and these are the major part of the cost quoted - for example, something like

 

[wozz]

If it was my house it would be RCBOs. I only ever fit RCBOs, although they are more expensive once i explain the benefits to the customer they never want a dual split board.

As a guide i pay

 

[Manator]

Thank you for the update

 

[confused]

Thanks for the advice, Wozz. It is good to hear someone recommmend RCBOs.

I like your suggestion to use RCBOs in multiple single phase boards. It makes a lot of sense and it should cut the cost considerably.

I will ask my electrician to quote on that basis using the Square D DOM RCBOs in multiple single phase boards, as he sees fit. Presumably, these Square D DOM RCBOs should be fittted into Square D single phase boards? Maybe there is light at the end of the tunnel.

Cheers.

 

[wozz]

yes i cant see a reason for fitting them in any other boards, the boards cost next to nothing as do the main switches. and im a stickler for manufactures instructions.

i ordered 12 of them and a 16way board for a extension yesterday! when the house gets rewired it will probably have a similar sized board serving that.

 

[jl-heating]

as above rcbo`s all the way if affordable...

still a major concern the load on a single phase .. !

even with diversity i would say well over

on another note if you use a mcs accredited installer. cash back as below

The Renewable Heat Incentive (RHI) is expected to commence in April 2011. It will provide an annual cash back payment for renewable heating systems such as heat pumps and solar systems installed after 15 July 2009. It will apply to home owners, private landlords, housing associations, social landlords, local authority buildings, community organisations and businesses.

The RHI has been calculated by the government to provide a 12% return on investment on heat pump installations and a 6% return on solar thermal systems. Payments will be made annually for between 18 and 23 years.

The value of the payment will depend on the technology installed and the size of installation. Very large commercial schemes (> 350kW) will have meters to measure the amount of kilowatthours (kWh) of heat produced. All other schemes will be based on the "deemed

 

[confused]

Many thanks for the information on the Renewable Heat Incentive, which I was already aware of. Our systems are both installed by MCS accredited installers and do qualify. I just hope that the new government doesn't change the policy before the new scheme is introduced next April.