Help Designing a Wiring System

[ban-all-sheds]

Asking questions on a forum is no different from reading a book,

It is hugely different.

Reading a book, assimilating the information and using it to help you come to a conclusion is so different from coming onto a forum and asking others to tell you what the answers are to specific questions you've been asked by those tutoring you for a qualification that, quite frankly, your position beggars belief.

As I said, if you disapprove, you are free to just ignore it.

I disapprove so strongly that I will roundly criticise people asking, and answering, questions like that.

Lecturers set coursework because they need to know how students are progressing. If students get other people to answer questions because they can't then they are misrepresenting their progress to their lecturers and are leading their lecturers to believe that their teaching is adequate when maybe it is not. Do it in an exam and it's called "cheating".

If Ryan doesn't understand voltage drop calculations for ring finals, then his lecturer needs to know that he doesn't.

 

[JohnW2]

Asking questions on a forum is no different from reading a book,

It is hugely different.

We will have to agree to disagree, then. Needless to say, I don't approve of people asking others (via whatever medium) to "do their homework" for them, but asking for help with it is a valid part of the learning process.

Kind Regards, John.

 

[Tozzy]

I agree it's no good telling Ryan the answers without him knowing why you've given that answer; hence why elaboration on the subject is always important until the student fully comprehends and is able to give his own answers based on what he has learned.

Which would be best, a ring or radical circuit? I think ring due to the length.

Bear in mind though, just because a building is long doesn't necessarily make it more convenient to install the circuit as a ring. Based on what I have learned , it's only the fact that there are sockets running parallel that it's more suited as a ring, otherwise it would be best as a radial to save on the amount of cable required to run back to the CU but only if the floor area is no more than 50sqm. Think that's right, but If I made a mistake here then sparkies feel free to correct it

 

[Tozzy]

As far as I can remember 106 meters of 2.5 mm sq with 1.5 mm sq earth as a ring and 45 meters as a radial.

Forgot to ask, so you're saying max cable length in 2.5mm is 106 meters and 45 meters as a radial or do you mean this is the floor area? Also, when calculating, is it best to use cable length as a guide or floor area? Cheers and sorry i ask lots of questions!

 

[JohnW2]

As far as I can remember 106 meters of 2.5 mm sq with 1.5 mm sq earth as a ring and 45 meters as a radial.

Forgot to ask, so you're saying max cable length in 2.5mm is 106 meters and 45 meters as a radial or do you mean this is the floor area?

He meant cable length, and was talking about the maximum cable length that would be compliant with the regulations in relation to the maximum permitted voltage drop.

Also, when calculating, is it best to use cable length as a guide or floor area? Cheers and sorry i ask lots of questions!

As above, you always have to consider cable length, so as to be sure of compliance with the regulations in terms of permissible voltage drop. Floor area is a guide, but only a very rough guide, to the amount of power that is likely to be required in a given room/space, hence the number of circuits (one or more) ideally required for that space - but it's only a guide.

Kind Regards, John

 

[RyanM]

Thanks for all the replies guys.

I can see where Ban-all-sheds is coming from, but I do a lot of research on the internet rather than go to the library (different generation perhaps?), and generally asking questions doesn't always give me the answer, but a lot of people, especially on here point me in the right direction of where to look for the correct answer!
I cannot ask at college due to it being the holidays, and I would like to get ahead with my work.



Thanks

 

[JohnW2]

Thanks for all the replies guys. I can see where Ban-all-sheds is coming from, but I do a lot of research on the internet rather than go to the library (different generation perhaps?), and generally asking questions doesn't always give me the answer, but a lot of people, especially on here point me in the right direction of where to look for the correct answer! I cannot ask at college due to it being the holidays, and I would like to get ahead with my work.

As I wrote to BAS, although I obviously don't approve of students simply asking a forum (or anyone else) to "do their homework/assignments/whatever for them", that is not what you did - and, although BAS clearly disagrees, my personal opinion is that what you did was an entirely reasonable part of the education process.

Even in olden days, one of the main differences between school and 'higher' education was that the latter involved students utilising resources far beyond interaction with their teachers - and these days, the same is even true of school education.

Kind Regards, John

 

[KayBull]

I would be looking at two radial circuits my self. Probably 4mm 32amp radials (75m/sq each), or if lower demand, 2.5mm 20amp radials (50m/sq each).

Hi, this is what gets me but I don't know how to ask correctly. How would you extend an installation with 2 circuits when I assume they both run from the CU? They would be the same length surely so how what would you gain by having 2 separate circuits? Does anyone understand? Could do with someone making me a diagram So 2 separate circuits means you can go further with your installation to prevent volt drop but they'd both be the same length if you know what i mean lol. If someone replies, assume we're talking about 2.5mm square cabling, thx

 

[JohnW2]

Hi, this is what gets me but I don't know how to ask correctly. How would you extend an installation with 2 circuits when I assume they both run from the CU? They would be the same length surely so how what would you gain by having 2 separate circuits? Does anyone understand? Could do with someone making me a diagram

It depends upon the actual 'geography' - and if it was as the OP drew, I agree it would make very little difference. However, try to imagine (to save me drawing!) a CU 'in the centre' with a series of sockets going roughly in a straight line for 25 metres to the left of the CU, and a similar line of sockets going off for 25 metres to the right of the CU. That could simply be done as two 25m radials. If you wanted to wire it as a ring, you would have to add a further 50m long cable, joining the right-most socket to the left-most one.

So 2 separate circuits means you can go further with your installation to prevent volt drop but they'd both be the same length if you know what i mean lol.

That's not necessarily true, since the voltage drop with a ring is roughly half that of a corresponding radial circuit, since there are effectively two cables in parallel feeding each socket. Measured at the 'middle' of a ring, the voltage drop will therefore be half of what it would be if one 'broke' the ring at that point, making it into two radials.

Hope that hbelps.

Kind Regards, John