Square D Distribution Board

[confused]

Hi,

I'm in need of some advice please. I'm currently building a new house with single phase supply. I have been told that a standard 17th Edition CU as originally specified is insufficient for the number of circuits in the house. Hence, a 36 way distribution board has now been specified by my electrician - making the price jump from around

 

[sellers]

How big is your house? How many circuits do you have? You can use 2 or more standard domestic boards? 36 circuits is a hell of a lot for a house??

 

[confused]

The house is about 380sq metres. I'm not sure exactly how many circuits there are; I believe something over 30. We suggested to our electrician that we use two smaller boards - as friends of ours with a similar sized new house did just two years ago - but we are told that it contravenes some code (NICEIC?) and that our electrician therefore will not fit (he said something about the fire brigade needing a single switch to turn off the power to the house). We are committed to using this electrician, who has now installed most of the wiring and we obviously need him to sign off the works.

The house features a ground souce heat pump (14kW, feature a starting current of 50 amps with soft starter and fuse rating of 32A), heat recovery and vetilation system, biodisc sewerage system, solar hot water heating, a pump to bring water from our bore hole to the house, and a considerable amount of lighting (mainly downlighters, using LEDs). Otherwise, it is all standard stuff - kitchen (electric cooker, microwave, fridge, freezer, dishwasher, washing machine, tumble dryer), power-showers in the bathrooms, alarm system, fire alarms, and a healthy amount of double sockets.

 

[green-hornet]

There would be no problem installing smaller boards and is standard practice for distribution of power in larger installs. Each board can be individually isolated via the main switch for that board which would greatly enhance and maintenance. All the power can be switched from iether the main board or via a seperate customer isolator, as this is a new build this can be fitted before the first distribution board.

The fire brigade if required to disconnect the supply do so via the main cut out by pulling the main fuse, this practice ensures total isolation.

I would speak with your electrician about the various alternatives.

 

[Theorysparky]

Without seeing the plans or cct layouts heres what i think

100amp supply to isolator

isolator to service block

service block out to 1 15way

out to another 15 way

isolator provides isolation for both boards

one of th boards could be to another area of the house via SWA

other guys on here may have better ideas

 

[confused]

Thank you Green-hornet; that's really helpful and interesting.

I have tried suggesting to our electrician that we use two smaller boards, but he has dismissed it as not being good practice and made it clear that I don't know what I am talking about (that much is true!). He claimed it was against NICEIC standards. I'll have another go at trying to discuss other options with him - he's going to love that.

Thank you again!

 

[Theorysparky]

Confused

you have just had two posts from 2 sparks basically giving you similar options

and GH is NICEIC......

Guinness

 

[Andy™]

Thank you Green-hornet; that's really helpful and interesting. I have tried suggesting to our electrician that we use two smaller boards, but he has dismissed it as not being good practice and made it clear that I don't know what I am talking about (that much is true!). He claimed it was against NICEIC standards. I'll have another go at trying to discuss other options with him - he's going to love that.

Thank you again!

i think you need another electrician. he should be working to 7671 - not any NIC 'alternative'. there is nothing wrong with multiple boards - this is often done if additions are required, or not enough room for a single board

 

[ElectekAir]

The way i see it you don't really have a choice if that is what they want to do then you just have to go with it.

I don't Belive that there are any 'codes' as your electrician is saying it could just be a cost thing (he wants more money), and if he has already run the cables then it is too late to be changing his mind (should have quoted it from the start and he needs to take the hit for it) he won't do it again!!!!

One other point is the electrician NICEIC domestic installer or NICEIC approved contractor they are very much different a NICEIC domestic installer is not NICEIC reg he is a NICEIC domestic installer and for him to say otherwise is misrepresentation and NICEIC will jump on him for IT

X(

 

[sparky b]

i've seen plenty of properties with more than one cu, i reckon he's after more money. If he's un-willing to fit 2 I'd pay him for what he's done and get someone else....

 

[confused]

I have just checked and my electrician is both a NICEIC Domestic Installer and a NICEIC Approved Contractor. He is also PAT Approved.

Thank you to everyone - there appears to be a consensus that using two standard boards is standard practice and acceptable. I shall try to discuss again with my electrician, now that I have some informed views to share.

The original quote which we accepted was against the standard plans produced by the architect. This didn't include all of the circuits; these we clearly specified when we first met the electrician, before any work was started. We asked him for an updated quote and repeated this request on a number of occasions thereafter, but for various reasons it wasn't forthcoming.

The work subsequently started, and a standard 17th Edition Board was installed. Some months later we were advised that this board was insufficient, although this must have been known by our electrician at the start. He has agreed to replace the board and to charge us only for the extra cost of the new unit. That was acceptable to me, until he said that we needed a 36-way board costing serious sums of money, which right now we could really do without. He knows that, and hence, I don't think he is specifying the 36-way board on the basis that he makes more money.

Changing the electrician at this time does not seem desirable, and I fear it would lead to yet more delay and additional cost. I'd, therefor,e sooner work with him, but effective communication isn't his strongest attribute. Hence, this plea for help - for which I am very grateful!

Cheers.

 

[ElectekAir]

I have just checked and my electrician is both a NICEIC Domestic Installer and a NICEIC Approved Contractor. He is also PAT Approved.Thank you to everyone - there appears to be a consensus that using two standard boards is standard practice and acceptable. I shall try to discuss again with my electrician, now that I have some informed views to share.

The original quote which we accepted was against the standard plans produced by the architect. This didn't include all of the circuits; these we clearly specified when we first met the electrician, before any work was started. We asked him for an updated quote and repeated this request on a number of occasions thereafter, but for various reasons it wasn't forthcoming.

The work subsequently started, and a standard 17th Edition Board was installed. Some months later we were advised that this board was insufficient, although this must have been known by our electrician at the start. He has agreed to replace the board and to charge us only for the extra cost of the new unit. That was acceptable to me, until he said that we needed a 36-way board costing serious sums of money, which right now we could really do without. He knows that, and hence, I don't think he is specifying the 36-way board on the basis that he makes more money.

Changing the electrician at this time does not seem desirable, and I fear it would lead to yet more delay and additional cost. I'd, therefor,e sooner work with him, but effective communication isn't his strongest attribute. Hence, this plea for help - for which I am very grateful!

Cheers.

Just did a google search first page http://www.abmelectricaldistributors.co.uk/products/Consumer+Units/WYLEX/Big+Consumer+Units/Wylex+36+Way+Consumer+Unit/1485989600

36 way wylex

 

[jl-heating]

i look at it another way, i would not want a 30 way board in my house its a hell of a load when you can split the load of two consumer units. sounds like an idiot to me !

ur the client

if he is not up to the job drop him and get someone else in there should be no problem signing his work off with the correct test and paperwork used.

if its a new build it will be under a building notice so i would just do pir for the work and notify the work under the building notice.

 

[sellers]

It was 2k fitted which with 30 circuits to connect and test doesn't sound amzingly expensive. Using a hager board it was 1700, you can get the boards for 250 plus about 70 for breakers and then various other bits, so labour is probably about 1330. For me labour would probably be 800 (3days)

But why 30 circuits? Seems a lot! Do you know what they are all for?

Also if I were you I'd go for the wylex, all the brands you mentioned are good quality, you just have to be careful with cheap imported boards.

 

[NozSpark]

TBH like the other, I don't understand your electrician.. why he didn't let you know of this increased cost before I do not know..

But it is all about the money! as below

1 x Hager 12way TP&N DB (this would give you 36 single phase ways)

1 x Hager 100A 3pole switch disconnector incommer

36 x Hager SP RCBO

 

[ProDave]

The house features a ground souce heat pump (14kW, feature a starting current of 50 amps with soft starter and fuse rating of 32A), heat recovery and vetilation system, biodisc sewerage system, solar hot water heating, a pump to bring water from our bore hole to the house, and a considerable amount of lighting (mainly downlighters, using LEDs). Otherwise, it is all standard stuff - kitchen (electric cooker, microwave, fridge, freezer, dishwasher, washing machine, tumble dryer), power-showers in the bathrooms, alarm system, fire alarms, and a healthy amount of double sockets.

Sounds to me like all the "green" features of your new home are going to use a lot of electricity, i.e not very green after all.

14KW for a ground source heat pump? I think 14KW would fully heat a modern well insulated home, so not much energy saving there?

All the other "green" features only adds another 4 circuits, so that's 5 circuits for the "green" stuff plus all normal circuits.

So say 4 ring finals for the sockets since it's a large house, and 4 lighting circuits, a shower and a cooker, and that's only 15 circuits.

I just wonder if your sparky (or the architect) has gone completely over board with 30 circuits?

I think there's a real danger when building such a large house, that there is an assumption that you have lots of money so you can afford higher prices, so you need to be careful you are not being taken for a ride.

 

[ElectekAir]

It was 2k fitted which with 30 circuits to connect and test doesn't sound amzingly expensive. Using a hager board it was 1700, you can get the boards for 250 plus about 70 for breakers and then various other bits, so labour is probably about 1330. For me labour would probably be 800 (3days)But why 30 circuits? Seems a lot! Do you know what they are all for?

Also if I were you I'd go for the wylex, all the brands you mentioned are good quality, you just have to be careful with cheap imported boards.

Sellers it was

 

[NozSpark]

I just priced it in post #15

came out at

 

[confused]

Thanks, guys. I too had looked on-line at the basic cost of 36-way boards. However, without understanding what I am buying, I found it difficult to equate the basic costs to the final fitted cost quoted. Sellers - your breakdown brings some perspective to the cost.

I did speak with MEM Technical Support and they said that the RCBOs would cost something like

 

[NozSpark]

If it was me I'd ring him up this evening and tell him that you want a detailed quote before he returns to site.. i.e. if you don't get the quote then you won't let him carry on working and that you will not be paying for any down time for him to get the quote done.

Tell him you want a fixed price as you cannot afford for costs to spiral