Lighting circuit unusual problem

[DIYdave]

Can anyone help? I had a fault on a light cable running from under the floor on the landing(coming from a junction box) out to the dining room ceiling rose. i was getting a live metal box at the wall switch. I then disconnected the earth connection in the junction box and in the light swich and still got a live earth cable?

So I then replaced the cable from the landing to the ceiling rose and did not connect the earth at either end, but still got a voltage between the live/earth and neutral/earth. I got 240V on the live and when measured across the earth to live or neutral I get 110V

Could this be an induced voltage caused by the cable going through the floor joists in the same holes as ring main cables?

 

[breezer]

if you dissconected the earth at both ends which earth were you measuring to?

also your meter was set to AC wasn't it? (have to ask)

 

[stovesy]

Completely disconnect the cable at both ends (remove LN&E). The using a meter with continuity tester, check both live & neutral to earth.

I have seen this before when a nail or screw has penetrated the cable.

And to answer your final line - No this is not induction it is a fault or your earth is not grounded properly.

 

[breezer]

Completely disconnect the cable at both ends (remove LN&E). The using a meter with continuity tester, check both live & neutral to earth.

I have seen this before when a nail or screw has penetrated the cable.

And to answer your final line - No this is not induction it is a fault or your earth is not grounded properly.

sorry to say do not use it on continuity as this either says "yes or no" use it on ohms