Cable Size

[scoobydooby]

Can anybody tell me what page in the "on site guide" or the "regs"
It tells me how to work out the cable size for the job in hand?

I know how to work out watts over voltage to give me amps required, but need to find table that allows me to put the cable length(route) into the equation?

Cheers All.

PS, I am doing 16th soon, before anybody passes comment

 

[Big_Spark]

Scooby, it is not as simple as you seem to think it is.

The Tables you refer to are in the Regs book, if you cannot find them then perhaps you need an optician as they takes up about 40 pages. Further you need to now the type of cable you are installing and the installation method you will use.

When you KNOW the design current of the Circuit, and the Length of the circuit, then you need to look up the cables sizes in the relevent tables, then look up the corresponding votage drop for the cable size in question. When you have done this you then need to do a calculation to ensure that the volyage drop of the circuit is within the permissable limits set by the Regulations.

There are also correction Factors to take into account.

 

[scoobydooby]

thanks fwl, i was thinking just domestic for now, along the lines of method 1 using twin and earth, and for arguements sake about a 15 metre run, there is a great online calculator from tlc, a paperback version wouldbe spiffing

 

[Big_Spark]

Scooby, it is always best to know how to do it yourself manually incase that calculator goes offline. Also, that is only a guide, it should never be taken as the true answer.

 

[mapj1]

If you have a printer, a free paperback version, with a nice explanation of how to use it, is the cable chooser document on Kevin Boons site, See reference section. You could do worse than print out and staple together a copy.
Mind you the OSG covers this description pretty well too.