No earth wire in light switch

[Norrie66]

Hello all,

I have a light which has been run from the house to a connected outside brick built storage area which has a small conservatory built around it. The conservatory has no light and I wanted to disconnect the light in the storage area and run a light to the conservatory from the switch in the storage area. The switch seems to be an old type which has connection for only two wires and no earth connection.

The wires in the switch are as follows.

Two cables running into switch.

Two live red wires wired into Top and Bottom of the terminal.

The two black neutral wires wired off into an isolated connector block.

Two earth wires cut and not connected to anything.

The light in the storage area has been run off a connection somewhere from a light in the house. I can't trace where because the cable goes into the ceiling void but I presume it is from the nearest light which is in the nearest room (kitchen)

My problem is this: The light I am fitting needs an earth. Since the earth wires are cut off at the switch I need to use, I don't know if there is an earth connection at the other end where the light was run off from and I can't find this out because I can't trace it back. Secondly, why are the two neutral wires isolated in a connector in the switch and should they be connected in a new switch which has connections for earth,neutral and live. I have put new lights in the house before and spurred of extra sockets etc without problem but have not come up against this. In the absence of wiring the new light to the switch I can wire it to a plug without cable showing as I have a socket in the storage area but really would prefer the switch.

Grateful for any help/advice that can be given.

 

[Essex1]

You need an earth loop impedance tester to ascertain whether the cables you are calling an earth are in fact that.

If they are cut off and not connected in the existing switch it is quite possie that this has occured elsewhere.

 

[JohnW2]

You need an earth loop impedance tester to ascertain whether the cables you are calling an earth are in fact that. If they are cut off and not connected in the existing switch it is quite possie that this has occured elsewhere.

Very true. Do I take it that, if he could acquire such a tester, you are 'giving permission' to the OP to undertake such a test, I would think inevitably with live parts of the switch exposed?

Kind Regards, John

 

[EFLImpudence]

You need an earth loop impedance tester to ascertain whether the cables you are calling an earth are in fact that.

Surely that should be a dead test.

 

[JohnW2]

You need an earth loop impedance tester to ascertain whether the cables you are calling an earth are in fact that.

Surely that should be a dead test.

One would have thought so, but he appears to be suggesting that the OP should undertake an EFLI test. As I implied by my question, that leaves me rather confused about his position, given that he recently wrote:

Any electrician/responsible person worth their salt would NEVER give permission for an un-trained person to access live parts. It is at best irrisponsible at worst un-ethical and dangerous.

Kind Regards, John

 

[333rocky333]

Unless he is actually not an electrician, iresponsible as well as being unethical and dangerous

To the OP do you have a multimeter and know how to do a continuity test between the cut off earth and a known earth like a socket screw or similar

 

[winston1]

Light switches don't have a neutral. They have a live and a switch wire, in your case the two reds. The neutral happens in your case to pass near the switch but should not be connected to it. The two cut off earth wires should be joined in a block as well, but as has been said you need to make sure it is connected back to the MET.

 

[ericmark]

In the past neutral was not normally taken to light switches. The use of extra low voltage lighting has changed that as often no loop connections in the transformer.

But for outside lighting even back in the 1970's it was common to take the neutral to the switch. Today with RCD protection it is a very good idea to take a neutral to the switch but one does need to be very careful.

A double pole and an intermediate switch look very similar but are completely different so one needs to know is it really a double pole or is it an intermediate switch?

As to earths been there and done that in the past. Pre-1960's we did not earth lights and all fittings were non conductive. Today we still find houses without earths and in general only option is to use double insulated lights and switches simply anything metal is out.

I have as I have said tried to connect earth wires in the past only to find there is some connection which you can't reach. In a wall or loft space. So you can spend a lot of time to no avail.

You can with the power off test with a simple door bell with built in battery in fact we still call it belling out a circuit. I in fact like the buzzer means you don't need to see the meter.

Where the problem lies is giving instructions it is all very well saying use a 13A plug with wire connected to earth terminal only and with the power to house off it should not be a problem. But people seem to want to leave circuits energised all sorts of excuses like freezer will defrost.

The earth is not disconnected when you turn off the power so there is no need to have anything turned on. Be it a meter or door bell does not matter it's a case of point by point testing. The only problem is when the item you are comparing against is not earthed.

With RCD protection the earth quality is not that important as long as it's there. With out RCD protection then really it does need low ohm ohmmeters (they use at least 250mA in the test) or earth loop impedance testers and as said the latter is dangerous in the wrong hands.

Light switches don't have a neutral. They have a live and a switch wire, in your case the two reds. The neutral happens in your case to pass near the switch but should not be connected to it. The two cut off earth wires should be joined in a block as well, but as has been said you need to make sure it is connected back to the MET.

Not quite correct. When fitting lights to outside or outbuildings it is common to switch the neutral so any water ingress will not trip the RCD when lights are not in use.

If RCD protected then likely one could export as TT but before I would instruct how I would want to be 100% sure it is RCD protected.

 

[JohnW2]

With RCD protection the earth quality is not that important as long as it's there. With out RCD protection then really it does need low ohm ohmmeters (they use at least 250mA in the test) or earth loop impedance testers and as said the latter is dangerous in the wrong hands.

Whilst that may be electrically true (provided that the RCD was was working satisfactorily), I think it is probably wrong to give the impression that reliance on an RCD (and a 'not very good' earth) is acceptable in terms of the regulations.

Kind Regards, John