House Renovation - Electrical Design Help Needed

[seggzee]

Hello,

I am a structural engineer managing a house renovation project in Nigeria which involves gutting out most of the existing interior and replacing. This will include all electrics.

It is a simple 2 storey house, with concrete block construction.

I am intending to use local electricians for the installation work, but I would like the design to be to UK Standards and current IEE regs.

I have floor plans and interior design drawings, and would like some help from someone suitably knowledgable for:

1. Duct and Conduit Layouts
2. Cable sizing (incl. calcs if required)
3. Circuit Design and Layout, including Consumer Unit sizing

I am based in Waltham Cross, Hertfordshire, so if anyone is fairly local to look over the drawings and chat about the design, that would be perfect.

I will of course be happy to pay for your time. Please leave a message here in the first instance.

Thanks in advance

Untitled

• seggzee
• 9 Oct 2013
• 1

Untitled

• seggzee
• 9 Oct 2013
• 1

Untitled

• seggzee
• 9 Oct 2013
• 1

 

[freddiemercurystwin]

Better off asking in the Electrical section.

 

[seggzee]

Ok, thanks. Was not quite sure if this or the electrical forum was best. Will move it over.

 

[ericmark]

I would say much depends on what you want. To try to conform with IET regulations is great but in real terms what you need is something that suits you.

The IET is British and in Britain we have a damp humid atmosphere and our regulations reflect this. RCD and other safety items are designed to cope with our weather.

Even in the Falklands they have to adapt and they are very similar to UK although seasons are reversed.

Items like AC units will change the requirements and really this needs to be outside UK. Clearly the Part P regulations don't apply and much of what we do is to conform with daft UK and EU regulations.

 

[seggzee]

Thank you, ericmark.

I appreciate that some regional effects will come into play, but I would like the basic infrastructure to be to UK standards, even if it is a slight overkill.

1. Yes, there will be air-conditioners, but should these ideally be on a ring circuit or individually wired from the Consumer unit?

2. What size cables to use for socket circuites, and which cables can run in the same conduits? how many conduits do we need to provide in the internal walls, etc

3. Should the lighting circuits be "loop in" or "loop at switch"?

4. Can the electrical circuits be split into 2 groups, one of which would have a generator / inverter back up supply?

These are the sorts of questions i would like some help with, so perhaps I was putting too much emphasis on the "UK Standards" aspect.........

cheers

 

[securespark]

What is the main supply fused at?

How is the water heated?

Are there solar systems for heating?

Is BS 7671 accepted in Nigeria?

There's a little about cable types and sizes here, and it mentions CAP 57 (is that the wiring laws?):

http://www.punchng.com/feature/power-talkback/stop-electrical-surge/

 

[EFLImpudence]

I think you are going about this the wrong way round.

It is up to you to state what equipment, appliances and accessories you want and an electrician will design the circuits accordingly.

I realise you said you wanted to find someone to do this for you but I would think that someone would have to be familiar with the Nigerian demands and practices.

 

[securespark]

According to Wiring Regulation in Nigeria as contained in CAP 57 of the Laws of Nigeria, “most house wiring should be carried out with 2-conductor 12 Amps rated cables with a nominal cross-sectional area of 1.0mm2 to 1.5mm2. While 3-conductor 15Amps rated cable with a nominal cross-sectional area of 2.5mm2 to 4mm2 could be used for AC units, water heaters and so on. All cables are made of PVC non-armoured single cored 2-conductor with bare ground/earth wire.”

What "single cored 2-conductor with bare wire" means, I haven't yet worked out!

Need to get hold o CAP 57....

 

[Iggifer]

lots and lots and lots and lots of radials then

 

[seggzee]

@Securespark

30A incoming, individual electric water heaters to each bathroom, no solar, and BS 7671 is accepted in Nigeria.

That link that you posted, and some of the responses to it, demonstrate exactly why I am looking for a UK equivalent design.

@EFLImpudence

Sorry, I dont quite follow what you mean. I cannot provide a list of appliances, and have never heard of one having to be provided for electrical design (unless its something specialised)

Its a domestic abode - lights, sockets, Split AC units and Water heaters.

Once I find somebody interested, I can go into more detail

 

[securespark]

No WH for the kitchen?

No solar? That does surprise me!

 

[scousespark]

The IET is British and in Britain we have a damp humid atmosphere and our regulations reflect this. RCD and other safety items are designed to cope with our weather.

I don't follow this. I don't recall ever being told we fit RCDS because of the weather.

Items like AC units will change the requirements and really this needs to be outside UK. Clearly the Part P regulations don't apply and much of what we do is to conform with daft UK and EU regulations.

Do you really belive that what we do is work to satisfy regulations? Aren't the regs just a framework to guide us towards safe installation?

As for the original post. There is a section entitled Electics Outside of the UK, where this thread belongs. IMO. The regs in Nigeria are the regs to follow. Randomly picking a country to see if there are better options is pointless.

 

[JohnW2]

Hi. Good to see you!

I don't follow this. I don't recall ever being told we fit RCDS because of the weather.

I must say that I had the same reaction!

Do you really belive that what we do is work to satisfy regulations? Aren't the regs just a framework to guide us towards safe installation?

I think you probably need to define that 'we'. What you say is, IMO, how it should be, but it is apparent that a substantial proportion of electricians do "work to satisfy regulations" - and, in their defence, it does seem that a fair bit of the 'training' of electricians these days majors on regulations, rather than electrical principles, 'thinking' or even 'common sense'.

Having said that, if a properly-trained electrician does something which (on the basis of his/her knowledge, judgement, experience and common sense) they are confident is 'safe', but find that it is non-compliant with a regulation, then maybe those responsible should reconsider the appropriateness of that regulation.

Kind Regards, John

 

[stillp]

Do they really use "PVC-insulated armoured copper cable with lead sheath " as claimed in securespark's link?

There's also a comment that “In fact, whoever would do the internal wiring must be duly licensed by the Ministry of Power, and not quacks” . Would "do the wiring" include taking responsibility for the design?

Personally I wouldn't want to design in the UK then use a local electrician to install anyway - better to work with a local electrician to produce a design that could be achieved with locally available materials and practises.

 

[Chri5]

I was lead project manager for BA Nigerias new offices back in 2002.

We had to show the local lads everything, the skill set was very in to doing it the African way which isn't what we wanted.

As for the OP I think you are being a bit cheeky since you are being paid to do the work you need to consider your liability to the client and consider employing or contracting out the design and the work.

Once you have the suggested design I'm sure we can help, but it seems a tad naughty for you to want some guys of the nets to design a solution for you.