Insulation Resistant test

[GPack]

Hi,
I did an insulation resistance test using Live and Neutral together to earth. I got a reading of .07 ohms. What could be causing this? Other than poor insulation.
Thanks

 

[Spudnik]

Bad connections on circuit, faulty meter.

 

[Hawk81]

What type of circuit? Lighting, Sockets? Need more info to help.

 

[nickblake]

If the circuit was working prior to the testing i would put my money on a neutral to earth fault , where the neutral has been trapped or caught by the face plate screws

 

[Adam W]

Could something still be plugged in, eg surge protector?

 

[GPack]

It was on a ring final circuit.

 

[GPack]

there may well be something plugged in. Would this make a difference on a neutral & Live to Earth test?

 

[nickblake]

test N to E then L to E see which one thats causing the fault as you have said you have joined the LN together , still place my money on a trapped neutral

 

[Marvo]

Hi,
.....I got a reading of .07 ohms.........

I've never seen an insulation tester that can measure a resistance of .07ohms. That kind of resistance isn't so much an insulation fault as a direct short to earth. What tester were you using and what test voltage was it set on? Can you describe the testing procedure in more detail?

 

[GPack]

Sorry, my mistake. .07Mohms

 

[Adam W]

there may well be something plugged in. Would this make a difference on a neutral & Live to Earth test?

Could be, if it's a surge protector.

 

[GPack]

How do the surge protecters work?

 

[Marvo]

They allow high voltage transients to pass through them to earth. There are various types of surge arrestor available with different clamping voltages etc.