Double insulated down lights cpc

[GBDamo]

The conductor is still not enclosed for protection.

Then no T&E CPC is, ever?

 

[westward10]

This is not an exercise in what I consider but what the book stipulates.

Please try to stick to the discussion rather than trying to undermine contributors.

Not what I am doing but you have stated the cpc is not a protective conductor although cpc stands for circuit protective conductor.

 

[GBDamo]

Not what I am doing but you have stated the cpc is not a protective conductor although cpc stands for circuit protective conductor.

No 'I' haven't. I have said that the book does not include CPCs as Protective conductors, and it is very specific as to what is does include.

Why does it not specifically refer to a CPC as a Protective Conductor?

 

[westward10]

No 'I' haven't. I have said that the book does not include CPCs as Protective conductors, and it is very specific as to what is does include.

Why does it not specifically refer to a CPC as a Protective Conductor?

You are looking for something which is not there, I could be incorrect but BS7671 does not use the abbreviation cpc. I believe it is only in the definitions in brackets after Circuit Protective Conductor.

 

[westward10]

Interesting stuff, especially since i'm doing the 18th tomorrow.

The 4mm, if mechanically unprotected, rule is for "Protective conductors" the definition of protective conductors on P33 (BYB) does not mention CPCs but rather:-

"A conductor used for some measures of protection against electric shock and intended for connecting together any of the following:-
(i) Exposed conductive parts.
(ii)Extraneous conductive parts.
(iii)the main earthing terminal.
(iv)Earth electrode(S).
(v) The earthed point of the source, or an artificial neutral."

None of the above mentions or hints at CPCs.......

.....Except metal (none class II) accessories, which then makes the CPC a "protective conductor".


I think...

A cpc is relevant to (i).

 

[Toneyz]

All/most of the LED commercial downlights we fit have drivers that only allow one 0.75mm 2 core flex. Mostly we have plug-in LCM boxes and can wire flex to the plug if it is an MF plasterboard ceiling we use Click-Scholemore flow connectors.

 

[Nigel]

Looks like there are two sets of terminals, the other set under the cover on the left.
Feed in and feed out to the next fitting.
Really should have been made with an earth terminal.

It is not permitted for Class 2 items to have an earth connected to them.

 

[Toneyz]

It is not permitted for Class 2 items to have an earth connected to them.

I take the view that if you are looping in and out of fittings this is part of the circuit and should have a CPC and that where there is the final connection to a fitting not requiring an earth eg double insulated etc. it is permissible to use two core flex.

 

[Alextrician]

Did manage to find some small connectors. Used j501’s then t+e to the fitting with a small connector inside the cap. Lesson learned to not buy gash from screwfix

 

[Deleted member 26818]

It is not permitted for Class 2 items to have an earth connected to them.

They can have an earthed connection point (often referred to as a parking terminal) and can have a suitably insulated CPC pass through them.

 

[Toneyz]

Did manage to find some small connectors. Used j501’s then t+e to the fitting with a small connector inside the cap. Lesson learned to not buy gash from screwfix

Then why not two core flex from the J501 to the fitting?

 

[Alextrician]

Then why not two core flex from the J501 to the fitting?

I had flex in the van but just decided to take the earth to the fitting. Obviously not needed but just thought to myself it’s better being there than not. cover every possible problem

 

[stevethesparks]

This was answered by Dillb in post #2.
My preference is a wagolite with either 221's or 224 lighting connectors.

 

[Wilko]

They can have an earthed connection point (often referred to as a parking terminal) and can have a suitably insulated CPC pass through them.

Agree Spin - if I'm reading it correctly reg 412.2.3.2 says Class 2 shall have a protective conductor at the accessory.

 

[Deleted account]

Agree Spin - if I'm reading it correctly reg 412.2.3.2 says Class 2 shall have a protective conductor at the accessory.

So does that mean that this class 2 cheap screwfix light does not meet regs as it has made no cpc termination or allowance for terminating cpc within the enclosure.

 

[Spoon]

So does that mean that this class 2 cheap screwfix light does not meet regs as it has made no cpc termination or allowance for terminating cpc within the enclosure.

412.2.3.2 Except where Regulation 412.1.2 applies, a circuit supplying one or more items of Class II equipment shall have a circuit protective conductor run to and terminated at each point in wiring and at each accessory.


NOTE: This requirement is intended to take account of the replacement by the user of Class ll equipment by Class I equipment.

All depends on how you interpret it.
It doesn't say how it should be "terminated at each point in wiring and at each accessory."
Unusual for the regs not to be clear...... Go figure......

 

[Wilko]

So does that mean that this class 2 cheap screwfix light does not meet regs as it has made no cpc termination or allowance for terminating cpc within the enclosure.

Hi - as per Spoon's post it's not clear. I'd say the manufacturer not providing a parking space for the cpc doesn't make it easy for us.

 

[Deleted member 26818]

As I have already suggested, the solution is to strip the CPC back so that it can be terminated outside of the enclosure.

The minimum CSAs of 2.5mm2 and 4mm2 are not applicable as the CPC forms part of a multi core cable.

There is no requirement in BS7671 for terminations to be made within an enclosure.
However there is a requirement for this CPC to be terminated at the accessory.

 

[Deleted member 26818]

Go on then Westie, explain.
You get the hump when members disagree with you and don’t offer an explanation.
Put your money where your mouth is.

 

[westward10]

As soon as you strip the cpc back and put it outside the enclosure it is no longer contained within the cable sheath and hence Reg 521.10.1 would come into play.