Rating of electric cable used to supply cooker panels?

[AlanBeckett]

Can you have (new) Split Consumer Units on 17th Edition?
Theoretically, as far as I know, the Sparky should check and verify the whole System.
Brace yourself!

Alan

[pwdrive]

Out of interest here's the guff on A Wylex split unit:

http://www.electrium.co.uk/Wylex17th%20Edition.pdf

Lawrence.

[AlanBeckett]

Ah, Lawrence, that's the difference. Previously Split Units only had half protected by an RCD. Now it's essentially both halves uness you've got a very peculiar installation.
I've always protected all my circuits.

Alan

[pwdrive]

That's correct Alan, we have the Wylex one, each split has it's own RCD, the bedroom and bathroom lights are wired on an opposite split to the bedroom ring main sockets in the bedroom, it's possible that the kitchen is wired the same although I can't remember off hand. We are single story so no stair wells, landings etc.

Lawrence.

[ppppenguin]

Under 17th ed all circuits (with a few special exceptions) must be protected by RCDs. There must be at least 2 RCDs so that a single earth leakage fault doesn't trip all circuits. The best method is separate RCBOs (combined RCD/MCB) for each circuit but this is more expensive.

It is not permitted to change the fuseboard without testing the entire installation. This may involve a certain amount of judgement as to what parts, if any, need to be upgraded or replaced. Typical issues on older systems may include older 2.5mm cable which has only 1mm earth rather than 1.5mm and lighting circuits with no earth conductor at all. Neither of these is an automatic fail. The smaller earth conductor will be more than adequately protected by the new RCDs and unearthed lighting circuits can be re-used provided none of the fittings requires an earth. All these deviations must be recorded on the certificate that must be issued by the installer.

Also, a consumer unit replacement may only be legally done by somebody with "Part P" self certification approval or by notifying building control.

What happens in practice may be different and I couldn't possibly comment further.

[Radio Fixer]

"It is not permitted to change the fuseboard without testing the entire installation. This may involve a certain amount of judgement as to what parts, if any, need to be upgraded or replaced. Typical issues on older systems may include older 2.5mm cable which has only 1mm earth rather than 1.5mm and lighting circuits with no earth conductor at all. Neither of these is an automatic fail. The smaller earth conductor will be more than adequately protected by the new RCDs and unearthed lighting circuits can be re-used provided none of the fittings requires an earth. All these deviations must be recorded on the certificate that must be issued by the installer."

All very scary for me as that's what is going to happen. I just have to hope that the 'sparks' is more reasonable in his judgement than came across on site inspection with the builder. Its not just cost but the disruption and add on work that an unreasonable approach can cause. I really don't want to get in to re-decoration of walls in other rooms not on the current agenda.

So fingers crossed although I have already checked all light fittings for earths and all power points for being correctly wired.

thanks Gary

[ppppenguin]

This guide hasn't been updated to 17th edition yet but is otherwise a useful guide to a particular problem in older installations and illustrates a sensible and pragmatic approach to less than ideal installations. There may be others in the series which I haven't looked for.
http://www.esc.org.uk/fileadmin/user_upl...v2_web.pdf

PS: This is highly relevant: http://www.esc.org.uk/fileadmin/user_upl...TP_web.pdf Look especially at 4.1 and 4.2

4.1. There is no legal requirement that calls for an
existing electrical installation to be upgraded to
current standards.
4.2. However, there is a requirement under the Building
Regulations for England and Wales to leave the
installation and the building no worse in terms of
the level of compliance with other applicable parts
of Schedule 1 to the Building Regulations than
before the work was undertaken. (Schedule 1 gives
the requirements with which building work must
comply

[Radio Fixer]

"4.1. There is no legal requirement that calls for an
existing electrical installation to be upgraded to
current standards."

Encouraging Jeffrey, I'll not panic yet then!

thanks Gary

[Radio Fixer]

Before 'Sparks' came I took off all the wall sockets on the kitchen and 'other parts' ring main. I detached all the red wires and with a long reel of cable buzzed out the circuit and then drew it in CorelDraw. He was very impressed and said it helped a lot.

He did say "... that's a very big ring", which I had to agree. Original was two sockets in the back bedroom, then drop down to one in the dinning room and then out to a couple in the kitchen.

But I had extended out to 4 in a conservatory ! From here back into the kitchen for more points and out to a utility room for 4 more (Guilty again!). But its never blown a fuse or been any trouble in the 15 years or so since the last addition which was the conservatory.

So some wall bashing and tiles to come off but I have 70 spares so no problem. It all gets split up to 3 rings: kitchen, utility and lastly bedroom and dining room sockets and conservatory.

For cooker and hob power he will use the old 6mm cable for the cooker and run a new 6mm for the hob.

We got on fine and I don't see any problems really.

When I did the wiring I put everything in conduit but now days it seems to be a capping over the cable down to below work top height and then just loose lay below the kitchen units. I imagine that is now judged to be safe as everything is on an ELB.

Gary

[ppppenguin]

When I did the wiring I put everything in conduit but now days it seems to be a capping over the cable down to below work top height and then just loose lay below the kitchen units. I imagine that is now judged to be safe as everything is on an ELB.

Always was allowed. Certainly back to 14th edition regs you were allowed to bury T+E cable direct in the wall or run it clipped to the surface and you still are. There are details that have changed to do with exactly where you are allowed to run cables in walls.

One big change in 17th edition is that ALL sockets must be protected by an RCD. All other circuits must also be RCD protected unless certain conditions are met. The main exceptions are if the cable isn't buried or hidden in a wall anywhere along its length or, if buried, is run in a steel conduit or is armoured cable.