Cabling in wall cavity ?

[Rupert]

I am having a single story extension built and was wondering if it is acceptable to have the ring main cabling in the cavity to avoid having to channel out the walls ?

Graham

 

[Octopus]

Unacceptable.

A competent spark would tell you that.

 

[telectrix]

why channel, when the cables can be installed pre-plastering?

 

[Rupert]

Thanks for the quick responses.
We will be dot and dab plaster boarding so would normally channel out a bit to ensure that the plasterboard isn't impeded by the cabling.
Under the 17th edition what are the requirements for protecting the cable in this situation. The last electrician I had do some work for me said that we would have to either earth metal capping or fit an RCBO in the panel.

Graham

 

[Octopus]

All cables concealed in wall less than 50mm from the surface should be protected by an RCD or by 3mm capping.

Dot and dab is normally thicker than the cable.

So what has your sparky said?

 

[telectrix]

the cables will be well under the space behind the board. can be clipped, capped, oval tubed, but as murdoch says, unless capped with 3mm steel or in earthed metal conduit, must have RCD protection. your spark will know all this and advise you accordingly.

 

[Guitarist]

Thanks for the quick responses.
We will be dot and dab plaster boarding so would normally channel out a bit to ensure that the plasterboard isn't impeded by the cabling.
Under the 17th edition what are the requirements for protecting the cable in this situation. The last electrician I had do some work for me said that we would have to either earth metal capping or fit an RCBO in the panel.

Graham

As you are having an electrician carry out this work, why are you not speaking to him/her?

 

[telectrix]

i see a DIY (disaster in yonder) looming.

 

[Sintra]

Thanks for the quick responses.
We will be dot and dab plaster boarding so would normally channel out a bit to ensure that the plasterboard isn't impeded by the cabling.
Under the 17th edition what are the requirements for protecting the cable in this situation. The last electrician I had do some work for me said that we would have to either earth metal capping or fit an RCBO in the panel.

Graham

You are going to have to fit an RCBO regardless as the circuit is described by yourself as a "ring main"

 

[SirKit Breaker]

I will throw my two pennoth in as well.

All general purpose socket outlets must be RCD protected.

This means either the cable supplying the socket has to be RCD protected, or the socket outlet has to be one that incorporates an RCD. BUT, there are other requirements to consider regarding the application of the regs.

So as this is in the DIY forum, please accept my word that your circuits require RCD protection, end of.

Howard

 

[Phil L]

See above

 

[Rupert]

Thanks for the feedback. I am wondering what the significance is of me referring to a "ring main" making it a requirement that an RCBO be used as opposed to an RCD in a split panel that serves the circuit ?

 

[Octopus]

Get your sparky to explain it to you. It gets lost when trying to describe over the web

 

[Rupert]

I don't have an electrician on this job yet. I understand the difference between an RCD and an RCBO just wondered why there seems to be a preference to individual circuit RCBO's.
No sweat.
Thanks for the responses.

 

[telectrix]

I don't have an electrician on this job yet. I understand the difference between an RCD and an RCBO just wondered why there seems to be a preference to individual circuit RCBO's.
No sweat.
Thanks for the responses.

when he said fit rCBO, that's because it's a socket circuit. i assume he was thinking there may not currently be RCD protection. either will do. and just to be pedantic, it's a ring final circuit, not ring main. a ring main would be a distribution ring circuit.

 

[Rupert]

Thanks for the clarification. I am old school so ring main was the terminology I grew up with but I take the point. Ring final circuit it is from now on then.

 

[Guitarist]

I don't have an electrician on this job yet. I understand the difference between an RCD and an RCBO just wondered why there seems to be a preference to individual circuit RCBO's.
No sweat.
Thanks for the responses.

Are you planning on pulling cables yourself, and then hope to get a sparky to connect and sign it off?
If not, then it's easier just to get someone onboard now to explain what he/she will do and get you booked in.

 

[Badged01]

just wondered why there seems to be a preference to individual circuit RCBO's.

Better discrimination!

With an RCD (protecting multiple circuits) when it trips you loose all circuits on that RCD. With an RCBO protecting the one circuit, when it trips you loose just that circuit. RCBO's is a more expensive option so the RCD route is usual taken.

 

[Rupert]

Thanks again guys for the help.
The property had a full safety test when I moved in so I know I am starting from a sound position.
The electrical work required for my extension is in the form of additions to existing circuits so as such is not notifiable under Part P (2010). When I have further work carried out later that is notifiable, when completed, I will have the whole house retested.

 

[Octopus]

Thanks again guys for the help.
The property had a full safety test when I moved in so I know I am starting from a sound position.
The electrical work required for my extension is in the form of additions to existing circuits so as such is not notifiable under Part P (2010). When I have further work carried out later that is notifiable, when completed, I will have the whole house retested.

Having the house "retested" is different to it being notified.

 

[Rupert]

I do understand that.

 

[Guitarist]

Thanks again guys for the help.
The property had a full safety test when I moved in so I know I am starting from a sound position.
The electrical work required for my extension is in the form of additions to existing circuits so as such is not notifiable under Part P (2010). When I have further work carried out later that is notifiable, when completed, I will have the whole house retested.

The work must still be carried out by a competent person, plus have appropriate testing and certification carried out, regardless of part P

 

[Rupert]

I do not believe that the term "competent person" is quantified in BS7671 but as a general rule it is accepted that such a person should have the appropriate knowledge and skills to carry out the proposed work.

As you will know BS7671 did not legally apply to dwelling house until Part P came into play, hence my reference to notifiable work under part P.
Prior to the 2010 version of part P even a qualified electrician could only carry out very minor work in their own home unless they were part of a competent persons scheme or notified the work to building control. The 2010 version relaxed these requirements to be more realistic in domestic situations.

 

[Andy78]

The Electricity At Work Regs 1989, a statutory document, states the following in regulation 16 titled "Persons to be competent to prevent danger and injury"

"No person shall be engaged in any work activity where technical knowledge or experience is necessary to prevent danger or, where appropriate, injury, unless he possesses such knowledge or experience, or is under such degree of supervision as may be appropriate having regard to the nature of the work."


BS7671 has always applied to all electrical installations as the standard to which all installations must adhere.
Part P has nothing to do with BS7671.
Just because you don't have to notify certain work does not mean it should not be tested. All alterations must be tested by a competent person with appropriate equipment, and the results recorded on an appropriate test sheet, before the circuits are re-engerised and put into use.

 

[Guitarist]

I do not believe that the term "competent person" is quantified in BS7671 but as a general rule it is accepted that such a person should have the appropriate knowledge and skills to carry out the proposed work.

As you will know BS7671 did not legally apply to dwelling house until Part P came into play, hence my reference to notifiable work under part P.
Prior to the 2010 version of part P even a qualified electrician could only carry out very minor work in their own home unless they were part of a competent persons scheme or notified the work to building control. The 2010 version relaxed these requirements to be more realistic in domestic situations.

Sorry, but that statement just proves that you haven't got a clue.

 

[Rupert]

I think it is a little unfair to say I don't have a clue.........

I agree with the statement "BS7671 has always applied to all electrical installations as the standard to which all installations must adhere."
I do not dispute this fact.

Where there is a disconnect in this debate is the following :-
The IEE Wiring Regulations, now BS7671 have always been a legal requirement for electrical installations in all situations with the exception of dwelling houses in England and Wales. This situation changed on 1st Jan 2005 with the introduction of the Building Regulation Document P. As of this date they also became a legal requirement for dwelling houses.
As I stated in a previous post this meant that even a qualified electrician had to either be a member of a competent person scheme or notify the work to building control when carrying out even minor work in their own homes!
This situation has been addressed in two further amendments in 2006 and most recently in 2010.

In this debate I have been wholly referring to an individual carrying out electrical work in their own homes. As such BS7671 is the reference document that should be followed but not all work now has to be carried out by a person who is a member of a competent person scheme or notified to Building control if not.

Some home owners DIY work is therefore permitted.

These are the facts !!

 

[Octopus]

I think it is a little unfair to say I don't have a clue.........

I agree with the statement "BS7671 has always applied to all electrical installations as the standard to which all installations must adhere."
I do not dispute this fact.

Where there is a disconnect in this debate is the following :-
The IEE Wiring Regulations, now BS7671 have always been a legal requirement for electrical installations in all situations with the exception of dwelling houses in England and Wales. This situation changed on 1st Jan 2005 with the introduction of the Building Regulation Document P. As of this date they also became a legal requirement for dwelling houses.
As I stated in a previous post this meant that even a qualified electrician had to either be a member of a competent person scheme or notify the work to building control when carrying out even minor work in their own homes!
This situation has been addressed in two further amendments in 2006 and most recently in 2010.

In this debate I have been wholly referring to an individual carrying out electrical work in their own homes. As such BS7671 is the reference document that should be followed but not all work now has to be carried out by a person who is a member of a competent person scheme or notified to Building control if not.

Some home owners DIY work is therefore permitted.

These are the facts !!

Top tip for you today Rupert - don't think you can come on here like a leach and get us to design your extension for you, as we won't.

Yes you can do some work yourself, BUT to comply with the regs you certain works WILL need sign off to comply with the regs and the Law.

 

[Guitarist]

t.

Some home owners DIY work is therefore permitted.

These are the facts !!

Homeowners DIY work has ALWAYS been permitted, just as long as they are deemed "competent" to carry out any and all works undertaken. Whilst BS7671 is indeed not a legal requirement in itself, failure to adhere to the electrical regulations can be, will be, and on many occasions has been used in a court of Law to convict individuals and Companies.
As already said, testing of any work carried out must be undertaken in order to prove suitability for proposed and continued use, regardless of Part P.
As electricians, we have to cover our backsides and live in the real world. We cannot, and will not simply say "ignore the regs, because technically they're not a statutory document".
My statement that you don't have a clue was really referring to this "bigger picture" which most people outside of our profession are not aware of, yourself included it would seem.
Hope this helps.

 

[Badged01]

The IEE Wiring Regulations, now BS7671 have always been a legal requirement for electrical installations in all situations

Nope, BS7671 is a non-statutory document. Nothing legal about it at all --- though by following it you are highly likely to meet the legal requirements set out in for example the EAWR

This situation changed on 1st Jan 2005 with the introduction of the Building Regulation Document P. As of this date they also became a legal requirement for dwelling houses.

Nope again, Part P has nothing to do with making BS7671 'legal' for domestic properties. BS7671 still remains a non-statutory document although under Part P there is a legal requirement to report specific 'notifiable' work (e.g. installing a new electrical circuit)

not all work now has to be carried out by a person who is a member of a competent person scheme or notified to Building control if not. Some home owners DIY work is therefore permitted.

Yep, some DIY work is permitted that doesn't need to be reported under 'Part P' but this few and far between. But even if you do work that doesn't need to be reported (e.g. fitting an extra socket on an existing circuit) how do you then ensure you meet the requirements of BS761? Being able to electrically test/check your work is for most purposes beyond a DIYer -- how can you confirm for example if you have a Zs value that meets the regulations for your new shiny work or even that the polarity is correct?

These are the facts !!

Nope, not completely .....

 

[Rupert]

Thanks for the debate guys.
By the way I wasn't asking anyone to design my extension.
I will now bow out and let you professionals continue to earn a crust.
Just to leave you with a warm feeling, I can assure you that when my renovation has been
completed it will be fully compliant with and tested to the 17th edition and all necessary paperwork in place.
I am not a DIY bodger.