Confused ...IR readings

[Dannyg8810]

anyone shed some light?

100m run of 4mm nyy cable

New cable and getting 135meg ohm when testing surely this should be >999 on martindale mft

Checked cable and no damage(visual anyway)

I know it's well above minimum permitted but still

 

[davesparks]

Is the cable completely isolated, or are any conductors connected to a load?
How long was the test voltage applied for before taking the reading?

 

[Dannyg8810]

Is the cable completely isolated, or are any conductors connected to a load?
How long was the test voltage applied for before taking the reading?

Not long just usually press test and within seconds it gives me reading it's the et4000 if that helps

 

[Dannyg8810]

Is the cable completely isolated, or are any conductors connected to a load?
How long was the test voltage applied for before taking the reading?

Nothing connected just cable either side
I got 365 from the socket before this

 

[westward10]

Sounds like damp or contamination.

 

[Dannyg8810]

Sounds like damp or contamination.

It's the same give or take between all conductors ,would the reading of 135 be considered acceptable on a new installation cert? So for so many questions I'm fairly new to testing so these results threw me a bit and just filling cert out now

 

[Dannyg8810]

Sounds like damp or contamination.

Last bit of info for you

I had a 3m length left and tested that and got >999

 

[westward10]

Yes it is acceptable but for a new cable of only 100m I would expect above 200 meg.

 

[westward10]

So you are testing this with the conductors at both ends free and nothing connected although strictly speaking the cpc should be connected to earth.

 

[Dannyg8810]

Yes it is acceptable but for a new cable of only 100m I would expect above 200 meg.

At a test voltage of 250 I'm getting >200