Using Green/Yellow not as CPC

[sparkinlee]

Here's quick question...

Can I sleeve a green & yellow flex conductor with brown or blue to use it as a switched live or neutral?

I'm looking at a situation where I do not need the CPC connection (the timer switch I'm connecting to is class 2 insulated) but I do need live, neutral and switched live. So I'm wondering if I can use 3 core flex (so that the conductors are all insulated within the outer sheath, unlike T&E) and put a brown sleeve on the G/Y to use it as the switched live.

Thanks for your help, and sorry if this has been answered many times before!

 

[coomers]

To me all multicore cables be they t&e,3,4 or 5 core flex etc should incorporate a cpc,i dont have the brb to hand but think there might be reference to something like this,no matter how short the run is.

incuding all appliance flex?

 

[Paul.M]

All appliances that use more than 3.5mA needs an cpc providing.

 

[coomers]

All appliances that use more than 3.5mA needs an cpc providing.

better tell the mr dyson and mr flymo

 

[Paul.M]

better tell the mr dyson and mr flymo

Why, don't they comply with reg 543.7.1.2? Or am I misreading it?

 

[coomers]

Why, don't they comply with reg 543.7.1.2? Or am I misreading it?

you are misreading items of equipment with LEAKAGE of 3.5 milli amps these appliances are double insulated

 

[Paul.M]

Yep and we should be talking about fixed wirering and not flex to lawn mowers and vacuum cleaners.

 

[Deleted member 26818]

There is no requirement in BS7671 for multicore cables to contain a CPC.
In fact there is a note in the Tables for multicore cables in Appendix 4, which states "with or without a protective conductor".
I'd be very suprised to find Tables for current carrying capacity of cables that include cables without a CPC, if a CPC is a requirement of the Regulations.
As for over-marking conductors being a deviation and it being a requirement to record such on an EIC, what exactly is a deviation?
Any defects or omissions must be rectified before an EIC/MWC is issued.
Departures from BS7671 are allowed only if they afford the same degree of safety as would be achieved by compliance with the Regulations.
514.3.1 requires us to identify conductors by either colour or alphanumeric means.
514.3.2 requires that every core of a cable be identified at the terminations and preferably (but not necessarily) throughout it's length.
I cannot see that compliance with 514.3.1-2 would be either any form of deviation.

 

[coomers]

I agree with the above post,basically there is nothing in the regs that prevent oversleeving,i am not saying i agree or disagree with it but its a fact and not against the regs.

 

[Knobhead]

So you guys are quite happy to sleeve a phase conductor with Green/Yellow and us as a CPC or sleeve the Blue (neutral) conductor Brown and use as a live.
Where is the difference with using a fully insulated Green/Yellow conductor for another purpose if it is fully sleeved at the termination?

 

[truckster]

411.3.1.1 "A cpc shall be run to and terminated at each point in wiring and at each accessory" so you need the cpc. Use 4 core flex

 

[mickys86]

For this type of work you should use a 3 core cable. In T&E the cross section of the earth isn't the same as the lives; so earth shouldn't be used as permanent live. Just my opinion.

Correct me if I'm wrong ( I'm just the apprentice)

But your saying that the only reason you wouldn't use the cpc in Twin cable is the fact it's a smaller CSA?

Nothing to do with it not being insulated then??

 

[pushrod]

Correct me if I'm wrong ( I'm just the apprentice)

But your saying that the only reason you wouldn't use the cpc in Twin cable is the fact it's a smaller CSA?

Nothing to do with it not being insulated then??

If it was being used in 2 way lighting the smaller csa could easily cope with the CCC needed - you would not do it for the other reasons not least that every cable should have its own cpc so leave it to what it was designed for and everyone expects it to be there for.

 

[Goody]

The twin earth comes with 2xinsulated 2.5 mm conductors and a 1.5 mm un-insulated conductor (CPC), all the three wrapped round by a PVC outer layer. In case of damage to the outer layer the CPC gets exposed and if it’s a live conductor the consequences will be serious.

Again 1.5 mm is capable of carrying lesser current than the 2.5 mm ones and when the circuit tries to draw more current than normal (because the fan got jammed or developed a fault), then the cable gets hot possibly resulting in a fire.

So as pushrod says, “leave it to what it was designed for and everyone expects it to be there for.”

Cheers!

 

[Knobhead]

The twin earth comes with 2xinsulated 2.5 mm conductors and a 1.5 mm un-insulated conductor (CPC), all the three wrapped round by a PVC outer layer. In case of damage to the outer layer the CPC gets exposed and if it’s a live conductor the consequences will be serious.

Again 1.5 mm is capable of carrying lesser current than the 2.5 mm ones and when the circuit tries to draw more current than normal (because the fan got jammed or developed a fault), then the cable gets hot possibly resulting in a fire.

So as pushrod says, “leave it to what it was designed for and everyone expects it to be there for.”

Cheers!

As usual this thread has gone off at a tangent.

I’m sorry but I thought we were talking about a 3 core flexible with a fully insulated CPC, not T+E.

 

[sparkinlee]

I’m sorry but I thought we were talking about a 3 core flexible with a fully insulated CPC, not T+E.

That was my original question... but no matter!