A simple loft issue

[k.k]

Hello people, i was up in a friends loft earlier today looking at some wiring that he seems to be having trouble with.Its a simple set up of two lights( on ceiling roses) + the one switch. the wiring itself seems as it should (live to junction box, down to switch, switch-live back up to both lights via junction box, return paths via neutrals). but yet no lights working. Could it be where the power is initially taken from..as it seems to be taken from the upstairs lighting , but maybe the switch wire and not the loop. Also ,i believe he said he had taken readings of 241volts line/earth, neutral/earth but 0volts N/Line in the loft the day before ?
What do ya think ??

 

[rocker]

Yep, turn on all the 1st floor lights and I guarantee it'll work. Been taken off the switch wire I'd wager

 

[rocker]

Oh hang on just read the voltage bit. 240 line/earth AND neutral/earth? Are you sure?

 

[Marvo]

From the voltages you've tested it sounds like a missing neutral. You would get these results if the light was switched on and the neutral was just floating.

 

[k.k]

Oh hang on just read the voltage bit. 240 line/earth AND neutral/earth? Are you sure?

Yes.Im pretty sure. I'll double check in a sec. Is something cross wired as the tennents before were keen on doing electrical work, from what i could see

 

[k.k]

From the voltages you've tested it sounds like a missing neutral. You would get these results if the light was switched on and the neutral was just floating.

when you say 'floating',Do you mean the wire is there but is disconnected?

 

[k.k]

Oh hang on just read the voltage bit. 240 line/earth AND neutral/earth? Are you sure?

Yes Rocker, it was 241 volts both N/E and L/E but ZERO Volts L/N

 

[Deleted member 9648]

Yes Rocker, it was 241 volts both N/E and L/E but ZERO Volts L/N

Missing Neutral as already stated ......the voltage on N-E is through the lamps on the circuit ,from the live with nowhere to go.
Check back to where feeds are coming from until you get 230-240v Live-Neutral.

 

[k.k]

Missing Neutral......the voltage on it is through the lamps on the circuit from the live with nowhere to go.

Yes, i can see that now! There is NO neutral return path due to it being taken off a switch wire, yes thankyou !!
So in order for me to sort that, i would need to take power from the live, on the loop,is that right?

 

[Marvo]

Floating means it's not connected to the neutral of the supply so it's not necessarily at zero volts with respect to earth, basically the neutral can become live.......so watch your eyebrows ;-)

 

[SirKit Breaker]

If the neutral has come out of its connection, then you will get supply voltage on it to earth, it has in effect become the end of the live circuit, hence IT WILL BE LIVE and IT WILL HURT, the neutral is a current carrying conductor, dont make the mistake of assuming it isn't. Make sure you use a proper meter to test it with, and isolate circuit before reconnecting. Dont want to teach you to suck eggs, but if you are not sure, then get someone who is.

Cheers........Howard