kitchen rewire

[thomo27]

Hi guys just after some advice..
Called out to see a customer who is getting a new kitchen..all plaster has been removed showing all cable runs some good some bad.. I explained id give him a price to add extra points and remove /re route cables into safe zones..he has an old fuse board non rcd protected and the cables arent protected I explained about a new board with rcd protection and didnt want to know..I can only otherwise suggest feeding an rcd unit and wiring the ring through the rcd...grrrr

 

[PrenticeBoyofDerry]

You do not need to RCD protect the existing cable, but any newly installed cable that will be buried less than 50mm, will require RCD protection, as will any new socket outlets.

 

[JohnW2]

You do not need to RCD protect the existing cable ....

Now there's an interesting one If the existing cable had been 'undisturbed', you'd obviously be right. However, if all the plaster has been removed, exposing the 'existing cables', is it acceptable to now re-bury them (less than 50mm deep) without RCD protection? I suppose what I'm asking is whether they still count as 'existing cables' after they've been unburied and then re-buried!

Kind Regards, John

 

[thomo27]

Its going to be on the existing ring so I will have to rcd protect all cables

 

[riveralt]

You do not need to RCD protect the existing cable ....

Now there's an interesting one If the existing cable had been 'undisturbed', you'd obviously be right. However, if all the plaster has been removed, exposing the 'existing cables', is it acceptable to now re-bury them (less than 50mm deep) without RCD protection? I suppose what I'm asking is whether they still count as 'existing cables' after they've been unburied and then re-buried!

Hardly interesting given the circumstances.
If the OP wants to have additional sockets then an RCD is required - new board ideal - garage type unit incorporating RCD and RFC for the kitchen acceptable.
The existing cables are a red herring - the electrician is only obliged to ensure that new sockets meet with the current regulations and that the old installation is not left in a worse state.

 

[PrenticeBoyofDerry]

Its going to be on the existing ring so I will have to rcd protect all cables

So you are extending the RFC then?
If so you have options:
*Mini RCD CU purely for RFC.
*External of board 30mA RCD to cover all circuits (not a good option)
*Mechanically protect all new cable and put RCD socket plates on new outlets.
*Tell the guy, it's new board or you walk away.

I assume the board cannot be fitted with RCBO?

 

[JohnW2]

Hardly interesting given the circumstances.

I agree - but it was PBoD, not me, who chose to comment that 'the existing cable did not need RCD protection', and it was that general statement which I thought raised interesting question.

The existing cables are a red herring - the electrician is only obliged to ensure that new sockets meet with the current regulations and that the old installation is not left in a worse state.

The existing cable is certainly a red herring if there are going to be new sockets added to the ring (as opposed to spurs) which require the whole circuit to be RCD protected. However, more generally, I'm far from convinced that burying a currently exposed cable <50mm deep without RCD protection would be compliant with the regs, even if it were an 'existing cable'.

Kind Regards, John

 

[PrenticeBoyofDerry]

Now there's an interesting one If the existing cable had been 'undisturbed', you'd obviously be right. However, if all the plaster has been removed, exposing the 'existing cables', is it acceptable to now re-bury them (less than 50mm deep) without RCD protection? I suppose what I'm asking is whether they still count as 'existing cables' after they've been unburied and then re-buried!

Only required to RCD protect new cable and sockets, just because the existing cable has been exposed, this does then not mean the requirement then changes automatically to :2008
Does noteven have to move existing cables in to safe zones, but not advising against it.

 

[riveralt]

*External of board 30mA RCD to cover all circuits (not a good option)

I was also thinking of that but dismissed it because I didn't think it was allowed under current regulations?

 

[PrenticeBoyofDerry]

I was also thinking of that but dismissed it because I didn't think it was allowed under current regulations?

I hear you, but I don't think the regulations absolutely dismiss, the use of one RCD covering the whole installation.

 

[riveralt]

However, more generally, I'm far from convinced that burying a currently exposed cable <50mm deep without RCD protection would be compliant with the regs, even if it were an 'existing cable'.

I'll work to the comments made by the HSE at the top of page 12 in the BGB - I'll let you worry about being convinced there is an issue here.

 

[JohnW2]

Only required to RCD protect new cable and sockets, just because the existing cable has been exposed, this does then not mean the requirement then changes automatically to :2008 ... Does even have to move existing cables in to safe zones, but not advising against it.

Maybe - but, as I said, I'm not sure. I would have thought that the spirit of current regs could be taken as saying "in 2013, thou shalt not bury a (currently exposed) cable <50mm deep if it does not have RCD (or mechanical) protection" (even if it had previoulsy been buried).

What if a bit of the cable had been damaged whilst removing the plaster? If you replaced the damaged bit of cable and then re-buried it (<50mm deep), would you still consider it compliant for that 'new' bit of cable to not have RCD protection?

Kind Regards, John

 

[DetlefSchmitz]

I'm pretty sure you are over-thinking this.

 

[PrenticeBoyofDerry]

What if a bit of the cable had been damaged whilst removing the plaster? If you replaced the damaged bit of cable and then re-buried it (<50mm deep), would you still consider it compliant for that 'new' bit of cable to not have RCD protection?

If I had replaced damaged cable, I would not consider under spirit of BS7671 and PP that RCD protection would need to be added.

 

[JohnW2]

I was also thinking of that but dismissed it because I didn't think it was allowed under current regulations?

I hear you, but I don't think the regulations absolutely dismiss, the use of one RCD covering the whole installation.

The regs don't explicity dismiss/forbid a single RCD, but I personally would struggle to see how one could argue that one had complied with 314.1 if one had created a situation in which a single fault could take out all circuits in the installation.

Kind Regards, John