No earthing on lighting circuit

[KevinH]

Hi all, I've been asked to make an old 4 story townhouse "safe" and issue cert for renting out.
Hasn't been touched for so long it has bakerlite accessories with wood backing!
Straight away I'm seeing replace all accessories, replace CU, upgrade earthing. The wiring is all in PVC cables but typical no earthing on lighting circuits.
I hear you all scream "REWIRE"!
Problem is property is highly decorated and furnished and owners would rather not go down that route.
My question is, if I fit all plastic accessories throughout, and clearly state on CU and cert NOT to fit any metallic fittings. Can I get away with that?
Just asking as whenever I've come across this problem in past, I've always rewired lighting so bit unsure what complies.
By the way, I've done quick IR, ring loop tests, Ze etc and all ok, but how do you R1+R2 lighting with no earth?

 

[westward10]

Are accessories double insulated, no they have exposed terminals to the rear of them.

 

[Nigel]

Here's an interesting addition. I re-read the ESC best practice guide on consumer unit changes prompted by this thread. Section 10 deals with situations where lighting circuits have no cpc.

View attachment 47181

Not sure what the relevance is unless the op was suggesting a re-wire with no cpc.

 

[Andy78]

Not sure what the relevance is unless the op was suggesting a re-wire with no cpc.

I'll be honest, I'm not entirely sure of the relevance either, but I took it to suggest that the method of using class 2 accessories, mentioned in the same section, should not be employed in a domestic situation. Otherwise what would be the point of putting it in the guide to consumer unit changes ?

If we are to ascertain that all existing equipment is safe for the alteration before work commences (132.6),
and if 412.1.3 deems that the method of double insulation is not to employed in a domestic situation, then we cannot fulfil our obligation to the requirements of 132.16 if it is employed.

 

[Ian1981]

Interesting points from both sides of the argument but I can’t see how you can class something as potentially dangerous if plastic accessories are fitted throughout the lighting circuit(s).
On the other hand an unearthed back box tho not necessarily accessible to touch could become live through breakdown of the insulation and if the homeowner was to decorate the wall then the added influence of water could have dire consequences.
Yet as stated there’s no law to say an installation must be upgraded to current standards.
The obvious problems start when we alter the circuit and installation and we need to comply with 132.16.
What I do know is, it does seem to be an acceptable practice in the industry to label the DB and have only plastic accessories throughout the circuit
Think I need a lie down

 

[Ian1981]

Indeed such an approach is not actually recognised by BS7671 - I bet no-one can find the wording of any such label within any Edition of the Wiring Regulations.

There’s a requirement to provide labelling at the DB for circuits with high protective conductor currents but no such label exists in bs7671 so it’s a similar situation label wise I mean.
The label for protective currents above 10mA is required by bs7671 in section 543 and is mentioned so perhaps that is indeed the big difference between the 2.
Often labels required are not actually in the wiring regulations themselves.

 

[Risteard]

There’s a requirement to provide labelling at the DB for circuits with high protective conductor currents but no such label exists in bs7671 so it’s a similar situation label wise I mean.
The label for protective currents above 10mA is required by bs7671 in section 543 and is mentioned so perhaps that is indeed the big difference between the 2.
Often labels required are not actually in the wiring regulations themselves.

OK, but the fact remains that not having a cpc terminated at every point in the wiring is not permitted by BS7671 for an ADS system.

 

[Ian1981]

OK, but the fact remains that not having a cpc terminated at every point in the wiring is not permitted by BS7671 for an ADS system.

No that’s a fair point

 

[Deleted member 26818]

As you are not installing the wiring then you don’t have to run a CPC and terminate the CPC at every point.
What you should do is provide RCD protection along with plastic accessories and the label.

 

[Taylortwocities]

What you should do is provide RCD protection along with plastic accessories and the label.

Agreed, I was going to raise that. Given the suspected age of the installation I would suspect that there is no RCD protection. I would want that, for a rented property, on the sockets at least.

 

[DPG]

Agreed, I was going to raise that. Given the suspected age of the installation I would suspect that there is no RCD protection. I would want that, for a rented property, on the sockets at least.

It shouldn't really make a difference as far as RCD protection if the person has bought or is renting the house. But I know what you mean.

 

[KevinH]

Thanks for all your helpful advice.
Just to clarify to the last few posts regarding RCD protection, I was planning on replacing the CU and ALL circuits would have RCD protection.
I would not be altering any cables in any circuits, just replacing accessories.
Also, I planned to replace all switches with plastic ones and use the push in plastic screw covers usually supplied with them, also all switches would be mounted on plastic surface backboxes to maintain the best insulation I can.
On a similar note, i'm surprised that they don't make labels to mount on/near the CU to warn of no earthing on lighting circuits, as i'm sure this is a common issue in very old properties. I'm assuming its just a case of getting the labelling machine out and typing something to that effect.

 

[Deleted member 26818]

It’s not a question of the labels not being made, more a question of them not being prescribed by BS7671.

 

[KevinH]

I stand corrected on my last post, turns out they do make "no provision for earth" labels. I just ordered some. I should have checked before sending post, oops.

 

[DPG]

Makes sense that someone has started knocking them out.

 

[Ian1981]

Makes sense that someone has started knocking them out.

Niceic do them with of course their logo on them