Insulation Resistance zero Ohms

[timhoward]

Last time I had something like this this it was a spur in the loft running a tv signal amplifier.
It took a while to find. The extremely good natured house-owner was looking at my tester and asked ask if we could send 1000v through whatever it was and track down the smoke!

As above, try a continuity test to get a better sense. If you have a socket adapter for test leads you can hunt it down as the closer you get to it the lower the resistance should become.

 

[KeenPensioner]

Thank you all so much, I've learned a lot and actually found what the problem was. It was a fused spur feeding a burglar alarm system. Thanks to everyone who took the time to reply.

 

[timhoward]

Thank you all so much, I've learned a lot and actually found what the problem was. It was a fused spur feeding a burglar alarm system. Thanks to everyone who took the time to reply.

Well done. Very satisfying when you find it!

 

[James]

Well done.
p.s. See post 5!!!

 

[EricMark]

Was the isolator switched off? If not then the neutral and earth are connected together by the DNO.

 

[DPG]

Was the isolator switched off? If not then the neutral and earth are connected together by the DNO.

He's found the problem, see above