Moved into a new house, lighting seems to have no earth

[enrabark]

Initially i measured live to earth, 110v, I measured live(red) to a pipe, i have 240v. So im assuming that i have lost the earth somewhere along the way to the light switches. however in the kitchen i have a seemingly good earth, Is it possible to run an earth from a socket to the lights, or from another light which has a good earth. Its fed from an old fuseboard, but i plan to get the board replaced with a modern rcd/mcb protected board relatively soon so i want to have to chase cables through the walls etc again when i come to change it. It looks like the light is wired up in a radial as there are only 1 wire coming from the fuse... Are there any obvious things that could possibly cause this fault? Or any uk regulations preventing me taking an earth from a working light switch/socket to feed this lighting circuit.
Any ideas or advice appreciated
Cheers

 

[SaladFingers]

Live to earth 110v, there may be a connection that's not so good. There can be other reasons, but I've seen that and it turned out to be corroded connections.

240v to earth, that's what you should be getting. As your earth refence is a pipe, it shows that the pipe as a connection to earth, nothing to worry about.

If you're worried, have someone carry out an inspection with the appropriate test gear.

What have you used, a normal multimeter?

 

[bernardgreen]

Your measurements indicate the earth wire in your lighting circuit is not continuous to the Main Earth Terminal. A lighting circuit without an earth is not hazardous PROVIDED there are NO metal switches or lamps that depend on the earth wire for safety.

That said you need to know where the earth is broken as it may be that critical earths to sockets are also disconnected from the Main Earth Terminal.

 

[enrabark]

cheers for replying men,

saladfingers: yeah i used a fluke multimeter, ive checked the other switches around, on both floors all connections seem ok. but for some reason im still only gettin around a 100v to earth on some of them. ive checked the earth connections in the board. everything seems tight.

bernardgreen: They are predominatly plastic, so it is possible that its been designed like that originally, i am gettin continuity between switches boxes. however i dont understand why there would be a earth wires inside the switch back boxes if it wasnt connected to the main earth terminal in the fusebox.

I just tried a new test (well, new to me) I put a short from the live lighting cct in the board to the earth rail, and went around the switches checking continuity from earth to the live wires, the switches which have been reading 240 were giving me a low resistance reading. the ones without were open circuit. This confirms the earth isnt gettin to these switches.

If it was originally designed for plastic fittings and switches i dont understand why there is earth wires in all the boxes with continuity between eachother but not to the earth in the board.

any help or comments are well appreciated

 

[EFLImpudence]

i dont understand why there is earth wires in all the boxes with continuity between eachother but not to the earth in the board.

Not much to understand, there should be.

It's already been said that you likely have a corroded or loose connection somewhere.
It's likely to be at a light fitting if that's where the earth loop is.
For example the earth wires may be in a terminal somewhere without a screw, or a similar situation resulting in poor contact.

I'm afraid you will have to discover where it is.
A clue to the location can be given by the position of good readings and poor.

 

[enrabark]

cheers, ive disconnected an inspected every light fitting and switch, couldnt find anything wrong with any of the earth connections but miraculously the earth continuity has reappeared. i have no idea which one had caused the fault but ive powered everything up and somehow everywhere is reading 240volts!
christ knows what has happened.
The only question remains and i doubt anyone here can answer it is, will this coming and going of earth continuity cause irritating tripping of and RCD when i replace the board with a new consumer unit.
thanks for all your help, its been a learning curve this has i tell you!

 

[SaladFingers]

Sounds as though during the retermination you've made good a poor connection.

 

[EFLImpudence]

will this coming and going of earth continuity cause irritating tripping of and RCD when i replace the board with a new consumer unit.

Not in itself.

 

[mfarrow]

will this coming and going of earth continuity cause irritating tripping of and RCD when i replace the board with a new consumer unit.

No it cannot. The main reason for nuisance tripping is a 'borrowed neutral' between circuits. Typically this is a landing light taking its neutral from the upstairs lighting, but being switched from the downstairs circuit. Easily fixed with a length of 1+E.