Ring Main Question

spakkker

What does the boiler do?
Electric underfloor heating?
I bet you have shares in your electricity provider!
Well this at least made me smile -Ta!

lisal0u

Hi again,

The oven says it has an average load of 1.1kw so originally we were just going to have it as part of the ring main. Then I thought if I ever change it it might be a problem if it has a bigger load.

The combi boiler is only small (Ideal mini) and supplies 4 radiators upstairs. I did a lot of research on electric underfloor heating and found lots of evidence that it is slightly cheaper to run than gas. Its more efficient and heats differently to radiators making it more effective. We will see though. Didn't have a lot of choice because there was nowhere to put radiators once we had moved walls around!

The 17th edition is very vague on a lot of things! This being one of them!

Thanks for your replies!

matbe

lisal0u wrote: »

Hi again,

The oven says it has an average load of 1.1kw so originally we were just going to have it as part of the ring main. Then I thought if I ever change it it might be a problem if it has a bigger load.

The combi boiler is only small (Ideal mini) and supplies 4 radiators upstairs. I did a lot of research on electric underfloor heating and found lots of evidence that it is slightly cheaper to run than gas. Its more efficient and heats differently to radiators making it more effective. We will see though. Didn't have a lot of choice because there was nowhere to put radiators once we had moved walls around!

The 17th edition is very vague on a lot of things! This being one of them!

Thanks for your replies!

The 17th edition is not vague it is very specific.The maximum recommended floor area for a ring main is 100 sq meters.

Ovens over 2kw should be on a seperate circuit.check the kw rating on the data plate on oven.

Part p does not require spare ways in the consumer unit but it is recomended.

All circuits with cables buried in the wall now require an rcd.

Check appendix 15 at the rear of the book.

lisal0u

Hi matbe,

Thanks for that! I've just worked out the floor area using the external house measurements and its 98m2. So will be a little bit less using internal measurements.

I don't know if its worth having a separate ring for the kitchen. Better to change it now then after we have boarded and plastered!

The council have checked the first fix and never mentioned that we only had one ring. I'm just worried that when they get their electrician (who is outsourced) in to check the final fix he will fail it due to it only having one ring. I'm surprised the council do the first fix check as they are only the building inspectors and not electricians!

I will get my Dad to check the 17th edition throughly so he can make an informed decision!

Thanks again
Lisa

mikey72

matbe wrote: »

The 17th edition is not vague it is very specific.The maximum recommended floor area for a ring main is 100 sq meters.

Ovens over 2kw should be on a seperate circuit.check the kw rating on the data plate on oven.

Part p does not require spare ways in the consumer unit but it is recomended.

All circuits with cables buried in the wall now require an rcd.

Check appendix 15 at the rear of the book.

Worth doing from a safety point of view anyway, but strictly only if buried less than 50mm, and not protected by an earthed steel conduit in a normal wall, but then there are also other exceptions that require it to be fitted. You also need discrimination, so ideally you're into two or more rcd's in the consumer unit as well if you need to protect everything, which you may not have with a 10 way consumer unit. If there is any doubt the on site guide is also useful, provided you know what's what in it.

lisal0u

Hi Mikey,

The consumer unit does have 2 rcd's and said it was compliant with 17th edition. All the wiring is protected with capping then boarded and plastered.

The house had a part re-wire before we bought it by a Part P registered electrician and it was a joke. Junction boxes everywhere, some not even with a cover on and they had managed to wire a socket via the lighting circuit!

mikey72

I've seen some horrors as well, by qualified electricians, but then I've also seen perfect jobs by diyers who done it straight from the book, word for word.
If you have the testers, the resistance and voltage drop will telll you if the ring is going to pass or not.
How have you split between the rcd's?

Canucklehead

matbe wrote: »

The 17th edition is not vague it is very specific.The maximum recommended floor area for a ring main is 100 sq meters.

Ovens over 2kw should be on a seperate circuit.check the kw rating on the data plate on oven.

Part p does not require spare ways in the consumer unit but it is recomended.

All circuits with cables buried in the wall now require an rcd.

Check appendix 15 at the rear of the book.

Hi

You should also note the length of the final ring for 2.5mm cable.. = 110 METRES at best.(dependant on fuse type) Source Section 4
Note mikey72's post on testing.

Corgi Guy.

ormus

mikey72 wrote: »

I've seen some horrors as well, by qualified electricians, but then I've also seen perfect jobs by diyers who done it straight from the book, word for word.

same goes for plumbers and so called CH engineers.

mikey72

Canucklehead wrote: »

Hi

You should also note the length of the final ring for 2.5mm cable.. = 110 METRES at best.(dependant on fuse type) Source Section 4
Note mikey72's post on testing.

Corgi Guy.

Section 4 of which reference book?