Ring mains length


Postby tigerman » Sat Jun 30, 2007 1:45 pm

What is the maximum length of a radial ring main allowed? and whats the maximum number of sockets can be wired in it?
tigerman
Rank: Apprentice
Progress to next rank:
0%
Posts: 5
Joined: Sun Jun 24, 2007 1:15 am

Sponsor

Simply Build It

Postby sparx » Sat Jun 30, 2007 3:47 pm

sorry, no such thing as radial ring main. Circuit is either a radial ie 1 cable from con unit out to 1 or more points or its a ring going out around area & back to start.
To clarify:
A1 ring- 2.5mm2 cable max floor area per circuit 100m2. on 30/32A
A2 radial 4.0mm2 " " " " " 75m2 on 30/32A
A3 radial 2.5mm2 " " " " " 50m2 on 20A MCB
Cable length are irrelevent as if above rules followed can't be too long!
Cooker circuits & lighting circuits also radials, & lengths are governed by need to keep circuit loop impedances low enough to trip circuits fuse/MCB in less than 0.4seconds, under fault conditions.
If above followed then no limit to number of socket outlets,
regards, SPARX
sparx
Rank: Project Manager
Posts: 2166
Joined: Wed Mar 21, 2007 8:33 pm
Location: The fifth continent.

Postby sparx » Mon Jul 02, 2007 2:22 pm

In addition to previous info. for radial circuits the total length allowed depends upon type of protective device at consumer unit ie rewirable, cartridge fuse, MCB (type 1,2 B,C,D)
so if you have a specifice circuit in mind we can give definitive answer,
regards SPARX
sparx
Rank: Project Manager
Posts: 2166
Joined: Wed Mar 21, 2007 8:33 pm
Location: The fifth continent.

Display posts from previous
Sort by
Order by



  • DIY How to Project Guides

  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!



 


  • Related Topics