DIY electrics question

[vib_ribbon]

i was up a ladder changing out an exterior light for my grandparents over the weekend.

i turned the mains off, but just to be safe i got the multi meter out to test the voltages before i detached the cable from the old light.

0v on the live + neutral.
but on the neutral + earth, it read 100v

i've searched this on google and skimmed through some articles.

question really, 1/ i've turned everything off, why's it still giving this reading? 2/ can it kill me? 3/ what can i do?

i ended up being extra careful, and got the job done in the end. so just need to know for the future really.

thanks.

 

[Muppz]

Borrowed neutral possibly?

 

[ZuPoint]

Did you turn all power off to house or just the one to turn the light out?
Poss. Cross circuits ( live from one neutral from another )

 

[philmurr]

I'm guessing you turned the circuit breaker for the circuit you were working on. This will (generally) only disconnect the live. So you'll definitely see 0V between live and neutral.

The earth and neutral are different - although in most modern builds they're tied together before the consumer unit so I think this has a different earthing arrangement.

So 2 things -

1) the neutral is picking up a voltage from other live wires it runs alongside (unlikely)
2) there is genuinely 100V (AC I presume) between your neutral and earth. Nasty and enough to at least give you a shock, but probably not enough to kill you because of the low current.

I'd seriously recommend you getting it checked out though, it's not right.

 

[anj]

It could be your tester giving incorrect readings , assume it live , and if your unsure turn the house off , and use test lamps not a meter to test