Responsible or not

[Bez]

I have been asked to install a new ring main and lighting in someones kitchen, which is getting a re-fit. All legit and above board through building control etc.I do not want to accept responsibility for the existing installation circuits, that have been worked upon by the home owner.

My question is: if you remove some socket outlets and remove some lighting points and then terminate the cables into appropriate enclosures, which will not be accecible for inspection, then would you then become responsible for the circuits, which you have removed the accessories from?

I'm bored with that row now.

Just thought i'de have a go at the original question.

As you are aware you must terminate the cables appropriately, either by the use of blanking plates, or take the cables up into the safe zone 150mm from the ceiling, or better still in the ceiling void if possible. (mechanical protection not a viable option in this instance, as you have to expose the cables to protect them, so you might as well move them)

You have now carried out work to that circuit so in my opinion you now have to include it on the EIC.

Further to this the Building Regulations state, "parts of the electrical installations in the building that were not subject to the work, should be no worse in terms of the level of compliance"

You will probably actually leave it in a safer state than when you started, although I accept your concerns that you will be signing for a circuit that most of which you can't see to inspect.

I think this is where the EAWR steps in with the words, "So far as is reasonably practicable"

It would not be practical to pull the house to pieces to check, cable routes, joist notches etc.

Make your terminations, test it, log it, and make a note of exactly what you have done.

 

[Andy™]

I'm still talking about T&E that is not in a safe zone.I'm pointing out to you that one of the options in 522.6.6 is not earthed steel conduit, but is in fact cable with an earthed metalic sheath.

a T&E has an earthed metallic sheath? thats new to me.

im getting bored with this now. if you want to continue and leave wiring in a potentially unsafe condition, go ahead.

 

[ianmacd]

Must be that snow again.

 

[Lurch]

I go out for a day and another couple of pages!

I'm pointing out to you that one of the options in 522.6.6 is not earthed steel conduit, but is in fact cable with an earthed metalic sheath.

But why, 6242Y (T&E) is neither of those so what relevance does it have?

And to add to another side argument that has spouted from this thread, I have run cables outside of safe zones, usually in galv tube, generally only on commercial jobs (schools springs to mind). Yes it would be better if it was i a safe zone, but it complies fully with BS7671 so there is no problem.

 

[spinlondon]

[quote name='Andy

 

[Andy™]

Now I am suggesting that T&E cable protected by an RCD has the same level of protection as a cable with an earthed metalic sheath that is not RCD protected.

no, its not the same level of protection/safety. as i have already mentioned.

back to the owner hammering a nail through it.

if its earthed metallic sheath (SWA, pyro etc), then the nail will be on contact with earth before it hits live, and will immediatly short to earth, tripping either RCD, MCB or both. point is, the nail can never become live to touch (even if there is no RCD, the circuit will disconnect via MCB)

if its a standard T&E, then you can easily nail the live conductor but not short to earth or neutral. the nail is now live, and will give a shock when touched. at this point the RCD should trip.

but, if the cable was installed to 522.6.6, the nail will never be live, in your 'safe method' the nail can be live. therefore does not give the same level of protection or safety.

so thats my side of it. now if you say it does offer the same level of protection, id like to see your reasoning of it.

 

[Lurch]

Now I am suggesting that T&E cable protected by an RCD offers the same level of protection as a cable with an earthed metalic sheath that is not RCD protected.

How so?

Now I've put forward a scenario, and as yet no one has put forth a coherent argument against it.

Probably because no-one really knows exactly what it is you are trying to say.

 

[spinlondon]

Remember that the cable with the earthed metalic sheath does not have an RCD protecting it. The nail penetrating the cable will operate an MCB hopefully within 0.4 with what ever current is flowing.

With T&E that is protected by an RCD, the RCD will operate in 40 milli-seconds, as soon as there is a path to earth with a current of 30mA.

 

[Lurch]

Remember that the cable with the earthed metalic sheath does not have an RCD protecting it. The nail penetrating the cable will operate an MCB hopefully within 0.4 with what ever current is flowing.With T&E that is protected by an RCD, the RCD will operate in 40 milli-seconds, as soon as there is a path to earth with a current of 30mA.

But that fault current could be flowing through a person, and could result in injury or death. If the cable is metallic sheathed then the fault current is flowing through the nail (in the case of the hanging a picture scenario).

So 6242Y and RCD is less safe than a cable with an earthed metallic sheath having no RCD protection. FACT.

 

[ianmacd]

40ms of current is still some therefore it can not be safer or as safe as a method that allows none.

If it was disconnected before someone was able to complete a circuit then it could be seen as 'as safe as' but this is not the case with your example.

 

[Andy™]

Remember that the cable with the earthed metalic sheath does not have an RCD protecting it. The nail penetrating the cable will operate an MCB hopefully within 0.4 with what ever current is flowing.With T&E that is protected by an RCD, the RCD will operate in 40 milli-seconds, as soon as there is a path to earth with a current of 30mA.

but like ive tried to tell you many times in this thread, with a T&E, the fault current could be through a person, but with the earthed metallic cover, the fault current will be direct to earth

 

[spinlondon]

Unfortunately, Andy you haven't.

All you've done is take the mick.

 

[Andy™]

Unfortunately, Andy you haven't.All you've done is take the mick.

really?

i would suggest you go re-read posts 76, 81, & 84, where i said that the fault current of your method would be through someone and the fault current by sticking to 522.6.6 would be direct to earth.

 

[Bez]

I think the general concensus of opinion is that it is safer to comply with 7671 when burying cables. We will doubtless all have our own differing methods of work, and I for one need to sleep at night, so I will go on following the BRB, rightly or wrongly until I am told by the next edition to change.

At the end of the day, the customer has to be safe and we need to cover our backsides.

 

[spinlondon]

My apologies, you did say that in those posts, you didn't start taking the mick until post 84

 

[Doc Hudson]

This particular thread has probably now covered its useful course, it is getting rather long and cumbersome for those reading to follow easily. The original question was addressed (and summarised at the top of page 9), various related issues have also been debated. I suggest we close it here and take any related issues to new threads if required.

Thank you for some interesting reading and debate.

Doc H.