S

StevieTee

Guys, looking for a little advice from someone with more experience regarding wiring this ring main.


I am re-wiring a full house, which has a new extension built onto the back of it. The extension has two rooms, a Livingston and bedroom. So, I have wired the old part of the house in 2.5mm for the sockets as it's a ring main and doesn't exceed 100m2.


In the new extension, I'm debating if I should wire the rings main in 2.5mm or 4.0mm. I have uploaded a picture with the details of the cable route and the position of the sockets.

Red dots are double sockets,
Blue is the route the cables are taking.

With the regards to the amount of sockets, this is what they are wanting.

I was thinking 2.5mm would do because it doesn't actually exceed 100m2, but was looking for a second opinion. All cables are ran under the house, so it's pretty cool under there temperature wise, though when the cable goes behind the wall, it passes between insulation.

cheers.
 

Attachments

  • image.jpg
    image.jpg
    288.9 KB · Views: 250
Last edited by a moderator:
As above.

I'm sure I've seen this 1:50 thing here before in a slightly different layout. Is this a homework question?
 
  • Like
Reactions: 1 person
Nah, it's a homer. Wasn't 100% sure about it, thought I would seek some advice from someone with more experience than meself.

Cheers lads.
 
Looks like you've got a 30m'ish ring serving just two rooms. Standard ring in 2.5mm on 32A breaker would do the job easily if cable run calcs support it. Otherwise a downgraded breaker would be OK as its just the two rooms -- living room and bedroom -- so I'll guess there wont be much demand!!
 
i'd do 2 x 20A radials in 2.5mm. on RCBOs, or at least, separate RCDs, that way, if you lose 1 room due to a fault, you still got the other one.
 
  • Like
Reactions: 1 person
Ring final circuit, not 'ring main'.

Your limiting factor is the load, and the potential Zs which will determine your cable size and circuit length, along with any de-rating factors.
The 100m2 guide in the OSG is just that, - a guide. In some cases it may not comply, so you should still think about load, current carrying capacity,potential Zs (length of cables) volt drop etc.
 

Similar threads

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electric Underfloor Heating Electrician Courses Heating 2 Go Electrician Workwear Supplier
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Advert

Daily, weekly or monthly email

Thread Information

Title
Ring main question
Prefix
N/A
Forum
Electrical Wiring, Theories and Regulations
Start date
Last reply date
Replies
12

Advert

Thread statistics

Created
StevieTee,
Last reply from
Andy78,
Replies
12
Views
2,583

Advert