ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Ring circuits UK style.

Paul,
what are the majority of homes in England constructed of????

Sparky:

The majority of houses are brick. There's usually a double brick outer wall with a cavity of about 3 to 4 in. between for insulation. Many older houses only have a single layer wall.

Internal partitions these days are usually timber frames with sheets of plasterboard; older properties had lath & plaster walls & ceilings. Some load-bearing internal walls are brick or block as well.

The roof is usually slates or tiles. American-style shingles are practically unknown.

This is what our real estate agents call "conventional" construction. There are some timber-framed houses, but they're rare compared to the U.S.A.

There are also one or two other styles, such as some very old houes built from stone and the pre-fabricated homes of reinforced concrete sections that were built quickly after WWII to provide emergency housing.

From the practical point of view, I think timber is by far the easiest to work with. Work on the old stone places is the worst.

Off Topic cont'd:

Have you worked with much Hebel Aerated Concrete Block ?

High insulation values (R-11 to 35) and you can shape and drill it with a 1" Spadebit and a 12V Drill! Neat Stuff... Getting more popular among the "hippies" around here, I've heard it's fairly popular in Europe.



[This message has been edited by sparky66wv (edited 09-23-2001).]

Paul,
is the fact that your homes are so solid the rationale behind the 'ring'? , is sounds hard to 'fish' wires thru what your describing.

Virgil,
if you find a link that can create some sort of viable building blocks out of manure, i'll cut you in for 50%

Virgil:

I don't recognize the name "Hebel," but aerated blocks are becoming more common in new construction now. One trade name here is "Thermalite" - Very light weight and easy to drill.

Steve:
Yes, running new cables can sometimes be very frustrating in homes here. Fitting outlet boxes etc. onto walls can also be tricky and involves a lot of hard work to chisel out a recess in the brickwork. Old brick & mortar can often crumble easily; I wish I had a penny for every time I've drilled and plugged a wall, then tightened the box to it only to have it fall out 10 seconds later!

I much prefer timber walls. I sure do love mobile homes.....!!


I understand they actually use such building blocks in some poor African countries. Maybe they collect the material from our Houses of Parliament..... (ouch!)

Paul,
how would you know if there is a break in the 'ring'

oh, about the manure crack, i just have more of it <animal> than i really need...... i'd be happy to oblidge any African relief effort

The possibility of a break going undetected is one of the downsides to the ring arrangement. In fact, if you think about it, there could be one break in the live and one in the neutral, but all outlets would still be energized with the possibility of a cable overload.

The IEE test prcoedures specify a continuity test between the two ends of each conductor before final termination into the fuseway/busbars. It's good practice to disconnect the wires and repeat these tests after any work on an existing ring.

hmmm,
very interesting! if you were to add a room on a home, would you "T" off of a ring, or make the ring bigger ?

It depends on how many outlets need to be added, in combination with the practical considerations of taping into existng wiring, running new cables with minimal damage etc.

A single-cable spur from the ring can feed only one outlet. Spurs use the same size cable as for the ring itself, so any more and there would be the possibility of the spur cable being overloaded. (A faulty appliance can't overload it because of the fuse in the plug - Max. 13A).

So, if there are only couple of new sockets in the extension and ring wiring near to each one, then it's often easiest to wire them as spurs. Otherwise, it's a case of breaking into the existing ring so that the new wiring becomes part of the ring. Sometimes a combination works the easiest. The Regs. also specify that the total number of spurs must no exceed the number of outlets wired directly on the ring itself.

Quite often, and particularly if there is a spare way at the main panel, it may be easier to wire a small extension as a new circuit. The IEE allows a radial arrangement using a single cable fused at 20A, subject to floor area limits for the circuit.

They also allow a 30A radial branch, but this means using a larger cable and is rarely seen in residential wiring.

Would there be any problem with attaching a new ring in a figure-8 arrangment rather than breaking the existing ring at any point?

That is, is it forbidden to have more than two paths to any outlet/junction?