I have searched Google, but get bombarded with "RCD" type answers. I read a few answers here that may have been relevant but turned out not to be, so I post my question. Being my first, I may unintentionally break some rules - hopefully not.
I was about to make a change to a domestic light circuit so tested the light socket to ensure the circuit was dead and I had pulled the correct fuse. (Yes this circuit is 50-60 years old, hence no CB!) What I discovered with the digital multimeter (set to 700V AC, as nearest higher setting) was that 33 AC volts existed whichever direction I connected the leads. And this is with the correct fuse removed!
Wanting to be more certain I used a light bulb to verify more digitally - i.e. 0 or 1.
I proceeded with the task which used the existing light wires as pull leads to get another cable down the wall. All finished I was set to reconnect the circuit exactly as before.
My understanding was that the Live wire went to the Common connection on the switch, so I reconnected the fuse and tested for the live wire with a neon single-connecton screwdriver and connected the one that 'glowed' to the Common terminal of the switch and the other to terminal 1.
At some point; either reconnection of the fuse or flipping the switch, the fuse blew. I have not replaced it, until I get to the bottom of this problem. So my questions are;
1 - first, does the live wire go to the common terminal on a two-way switch? (being used as 1-way currently, but hopefully soon to be two way).
2 - Has the neon screwdriver led me astray for which was the live wire?
3 - Is it possible that my house has neutral switching and if so, how do I find out? It has been illegal here in NZ for at least 60 years I would have thought. If neutral switching should I put the other wire to Common and the live one to terminal 1?
4 - Is 33 volts AC a concern when the circuit is off? I did not get any form of tingle when man-handling the wires. We have 240 V AC circuits in NZ for domestic wiring.
Thank you for any answers that you care to provide.