Responsible or not

[Andy™]

i still dont agree with you

if the cable is installed to 522.6.6 (i) - (iv), then you can leave it in the wall, anywhere, without RCD protection.

or you can install in a safe zone (522.6.6 (v). however, if its not under supervision of ...., then 522.6.7 states it must be RCD'd.

now if you have a standard T&E in the wall, unprotected (to 522.6.6 (i) - (iv), then it must be installed to 522.6.6 (v) (inside safe zone), which 522.6.7 then says it must be RCD'd.

so if you leave the cable outside the safe zone, you have not complied with 7671

and i still cant see where you got

If this is what you intend, I would further suggest that you put this ring on an RCD, as the cables may no longer be in safe zones.

from?

 

[Andy™]

I'l try and explain.BS7671 requires all circuits to have a CPC.

Do you agree yes or no?

The ESC advice, is that if there is no CPC on a lighting circuit, it is permissable to leave the circuit without a CPC, if you RCD protect that circuit and to ensure that all fittings ar class II.

yes, i fully agree with everything you have said in that post, but i cant see how this has anything to do with leaving a cable without mechanical protection and out a safe zone, in the wall simply by adding an RCD?

 

[Bez]

I'm getting confused (not helped by only part of 522.6.6 being written above!).I read it that Bez was saying that if a cable is in a safe zone it doesn't need an RCD, which 522.6.7 disagrees with.

I didn't mention the use of an RCD. my point was the installation of cables outside zones contrary to 522.6 (i), (ii), (iii), (iv). Whether it needs an RCD or not is a seperate issue to 522.6.6.

You are correct in your quotation of 522.6.7. Cables meeting 522.6.6 (v) need RCD protection

 

[Bez]

if it's outside the zones it needs mechanical protection.

 

[Andy™]

if it's outside the zones it needs mechanical protection.

i know!

 

[Bez]

Apologies for shouting but we seem to be going around in circles

 

[Bez]

I'l try and explain.BS7671 requires all circuits to have a CPC.

Do you agree yes or no?

The ESC advice, is that if there is no CPC on a lighting circuit, it is permissable to leave the circuit without a CPC, if you RCD protect that circuit and to ensure that all fittings ar class II.

What would be the point of an RCD on a circuit with no Earth?, How would it operate?

 

[spinlondon]

[quote name='Andy

 

[spinlondon]

What would be the point of an RCD on a circuit with no Earth?, How would it operate?

RCds operate by detecting an imbalance between live and neutral.

If there is an earth fault, then the current passing along the live will be greater than that passing along the neutral. The RCD detects this and operates.

 

[Andy™]

What would be the point of an RCD on a circuit with no Earth?, How would it operate?

RCDs work on imbalance. so if you get a shock, it will detect the imbalace through you and trip

 

[Lurch]

Think you need a copy of the BRB to get this now..... ?:|

I have, but it's the thread that confuses me. Like I said, I'm not even sure what the argument is any more.

 

[Andy™]

This solution does not comply with BS7671. It is a departure from the Regulations.However because it is considered to offer the same level of safety as compliance with BS7671 would offer. It is deemed acceptable.

Having cables outside of safe zones at a depth less than 50mm would not comply with BS7671.

Do you agree yes or no?

Do you see where I am going with this, or do I have to spell it out?

so we have many posts and now we find out your solution is a departure, and does not stick to 7671... you could have at least said that earlier.

having cables outside of a safe zone at less than 50mm would not comply with 7671 - at least we agree with something.

but i cant see how adding an RCD is considered to offer same level of safety? same level compared to what?

also, i cant see how your thing with RCDing an unearthed lighting circuit has anything to do with this?

so yes, it looks like you may 'have to spell it out', since i still dont see where your going with this

 

[Andy™]

I have, but it's the thread that confuses me. Like I said, I'm not even sure what the argument is any more.

spin says a cable can be left outside a safe zone, provided it has an RCD.

despite all the evidence against this claim, and no evidence to back it up form his side, expect something to do with a lighting circuit with no earth, i not even sure whats going on now?! this has went way OT!

 

[spinlondon]

I have, but it's the thread that confuses me. Like I said, I'm not even sure what the argument is any more.

BS7671 requires that cables concealed in walls should either be deeper than 50mm, have earthed sleeving, be in conduit or trunking, be mechanically protected or be in a safe zone with RCD protection.

The op wants to remove accessories and join the conductors and conceal them.

I have suggested that if he were to do so, the cables would no longer be in safe zones, and that he should RCD protect them.

A number of people disagree with me, because they state my suggestion does not comply with BS7671.

I am stating that it does not have to comply with BS7671 if my suggestion offers the same degree of safety as would compliance with BS7671.

I think that that is it in a nutshell.

 

[Lurch]

BS7671 requires that cables concealed in walls should either be deeper than 50mm, have earthed sleeving, be in conduit or trunking, be mechanically protected or be in a safe zone with RCD protection.The op wants to remove accessories and join the conductors and conceal them.

I have suggested that if he were to do so, the cables would no longer be in safe zones, and that he should RCD protect them.

A number of people disagree with me, because they state my suggestion does not comply with BS7671.

I am stating that it does not have to comply with BS7671 if my suggestion offers the same degree of safety as would compliance with BS7671.

I think that that is it in a nutshell.

I see, in that case....

[quote name='Andy

 

[Andy™]

BS7671 requires that cables concealed in walls should either be deeper than 50mm, have earthed sleeving, be in conduit or trunking, be mechanically protected or be in a safe zone with RCD protection.The op wants to remove accessories and join the conductors and conceal them.

I have suggested that if he were to do so, the cables would no longer be in safe zones, and that he should RCD protect them.

A number of people disagree with me, because they state my suggestion does not comply with BS7671.

I am stating that it does not have to comply with BS7671 if my suggestion offers the same degree of safety as would compliance with BS7671.

I think that that is it in a nutshell.

adding an RCD cannot offer same level of safety as sticking to 7671 - if you did the work to 7671 the cable would be either removed, or in earthed steel conduit or similar.

now suppose owner hangs a picture in kitchen - by working to 7671, the cable will either be gone, or protected from the nail by conduit etc.

working to your method of adding an RCD, the nail can go straight through the cable.

if you had an RCD, then yes, it should trip, but this may only be after there is fault current flowing through someone after touching the now live nail. by working to 7671, there would be no chance of that nail ever becoming live, so simply adding an RCD cannot give you the same safety.

 

[Andy™]

I can;t see what level of safety it maintains by taking a compliant 16th edition, only non compliance with the 17th being lack of RCD, and then making it comply with neither the 16th or 17th. This, in my view, does not offer the same level of safety, and I believe this is exactly why part p and some of the ridiculousness of the 17th edition was (misguidedly) brought about, but that's another topic.

it never complied with 16th either....

 

[Lurch]

[quote name='Andy

 

[spinlondon]

[quote name='Andy

 

[Lurch]

A departure from BS7671 is something that does not comply with BS7671, but that will offer the same level of safety that compliance would offer.Protecting cables that are outside of safe zones with an RCD would IMHO offer the same level of protection as if those cables had an earthed metalic sheath. In fact as the RCD will operate quicker than the MCB, it might be seen that it offers greater safety.

That might make it electrically safer in that an RCD will act faster than an MCB, and will also open in minor earth faults, but in general, it does not offer the same level of safety to the installation as a whole as you now have unprotected cables outside of safe zones. I think it would be a bit more than a departure, and I would not note it down as such.