length of ring main

[i=p/u]

is there a template electricians use for designing a job or isit your own piece a paper and pen.. just wonderin ya know me , no patience

 

[Paul.M]

I'll give you a question to answer your own question...... you have a house that is getting turned into 2 one bedroom flats. The main incomer is down stairs with the meter, another meter will be provided for up stairs. It is you job to install both c/u's. How would you do it and why? Answer later.

 

[i=p/u]

get the electricity board to extend tails once ive installed the circuits. how about that for quickness

 

[Paul.M]

You've got to extend the tails from down stairs to the new c/u but what would you do after the c/u in both flats? That's what I meant.

 

[Paul.M]

Ok I=p/u I'll give you a hand. Read these regs.313.1, 314, 314.2 (page 38 brb), 537.1.3+.4 page 118. Oh and the extended tails would have to have mechanical protection or a rcd.

 

[i=p/u]

well i know cable sizing , volt drop aall calculated first,

 

[Paul.M]

well i know cable sizing , volt drop aall calculated first,

All very well but the question is about planning main isolation switches and in this case I would split the tails from the incomer, isolation switch before each c/u to provide a means of safe isolation for each flat independently for maintenance and repair without causing any disruption to the other flat. Use logic and common sense. What happens if a fault occurs down stairs and blows main fuse for both flats and house holder is on holiday, freezer defrosts, water dripping in from upstairs etc. Always think what can go wrong.

 

[Adam W]

I know the original question is a week old now, but what's wrong with doing it in accordance with the regs?

 

[i=p/u]

do you split them usinh a isco just.................

All very well but the question is about planning main isolation switches and in this case I would split the tails from the incomer, isolation switch before each c/u to provide a means of safe isolation for each flat independently for maintenance and repair without causing any disruption to the other flat. Use logic and common sense. What happens if a fault occurs down stairs and blows main fuse for both flats and house holder is on holiday, freezer defrosts, water dripping in from upstairs etc. Always think what can go wrong.

 

[Paul.M]

Look at the diagram 2.1 on page 15 of the OSG. Split it from the electricity company isolator (that you may have to install) and take your feed from there to the flat above in swa or with mechanical protection, if not you will have to protect it using an rcd for the tails. Ps if your not experienced enough don't try it mate.