Earth and plastic

[DIYPaul]

Hi

I want to move a light switch for my indoor porch light from the hallway to the porch, without having to chase in new wires in the hall.

To do this, I've by-passed the existing switch with a wire connector, and put a new switch in the porch (note that the switch in the hall also operates another light).

First question...the switch and back-box in the porch are both plastic. Is the earth wire strictly necessary in this situation, if so what role does it play? Currently, I've just terminated it in the box.

Secondly...if I wanted to actually make this a two way switch (porch and hallway switches) without chasing in a new wire (the existing wire is twin + earth). Supposing the earch wire isn't doing anything in this situation, can I use that as the 'common' in the 2-way wiring schema? I'm aware this sounds very dodgy, but I really can't see that the earth wire actually does anything in this setup.

Thanks

 

[Des 56]

Paul you are considering doing something that is not safe
Making a light work is totally different to making it work safely

Consider getting a qualified spark to do the job

 

[SimpleSimon]

At this current point in time the earth wire plays no role as it is in an all insulated enclosure so terminating it with a chock block or green/yellow insulating tape is fine. However, in the future if you or someone else decide you want to change the switch plate to a metal switch this will than need to be earthed and the earth wire will be needed. (please note even now if you think "I won't be changing it" don't cut the earth as you never know the future ).
And no you won't be able to use the earth as part of a two way switch. This earth should be continuous through the circuit and terminated in the main earthing terminal. Using it as a live conductor will only cause problems.

 

[Sparky Ninja]

Hi

I want to move a light switch for my indoor porch light from the hallway to the porch, without having to chase in new wires in the hall.

To do this, I've by-passed the existing switch with a wire connector, and put a new switch in the porch (note that the switch in the hall also operates another light).

First question...the switch and back-box in the porch are both plastic. Is the earth wire strictly necessary in this situation, if so what role does it play? Currently, I've just terminated it in the box.

Secondly...if I wanted to actually make this a two way switch (porch and hallway switches) without chasing in a new wire (the existing wire is twin + earth). Supposing the earch wire isn't doing anything in this situation, can I use that as the 'common' in the 2-way wiring schema? I'm aware this sounds very dodgy, but I really can't see that the earth wire actually does anything in this setup.

Thanks

The earth is a circuit protective conductor and so is essential along it's length, not just at accessories.

Using a CPC as a line conductor is an absolute no no. I'm sorry but i think the only advise you will be receiving here is to call in an electrician.

 

[IQ Electrical]

I'll second that!

 

[telectrix]

i'll third it. get the chisel out or call in a spark

 

[Amp David]

I'll fourth it.

Looks like the new years bringing out a bit of DIY!

 

[IQ Electrical]

I'll fourth it.

Looks like the new years bringing out a bit of DIY!

Yes, Don't Involve Yourself!

 

[Amp David]

Just gonna sit back and watch with interest i think.

 

[oldtimer]

As I have said before I cannot understand any of this plus in this day and age as i keep repeating a couple of digital pics would be nice and would give us a starter i am quite happy to give out advice but let me leave you with this I got a call on Xmas eve the tiler has found a cable under the bath and the tenanat is freaking out could you phone them and tell them it is safe me said nope I am not Darlinda so I would need to check it out but if you are saying that the cable is terminated into a joint box then me thinks it is indeed live and will need checked out.

 

[Deleted member 9648]

I'm fifthing it.

 

[Guest123]

I'm reinforcing it to the 'n'th degree.

CPC is CPC for a reason.

 

[telectrix]

I'm reinforcing it to the 'n'th degree.

CPC is CPC for a reason.

they do some really nice gear at good prices.

 

[Marvo]

I'm also not good with using the earth wire as a part of the switching circuit. With FT+E, as with many other cables the earth wire can be a different material and it's not sized, insulated or designed to be at a potential other than zero and carry any load other than a momentary fault current.

Phone an electrician.