Changing IR with voltage

[newfutile]

On a recent EICR i have measured 0.589 MegOhms (@250 volts) on the relatively old lighting circuit (red/black PVC wiring) , i have replaced both outside lights (thinking water ingress as both were damaged).

The strange part is at 1000 volts the IR changes over a few seconds to 1.6 Megohms , it will stay at this value even at 250V for perhaps an hour.

Its a void property and been empty for a few months if this helps?

 

[Petej999]

On a recent EICR i have measured 0.589 MegOhms (@250 volts) on the relatively old lighting circuit (red/black PVC wiring) , i have replaced both outside lights (thinking water ingress as both were damaged).

The strange part is at 1000 volts the IR changes over a few seconds to 1.6 Megohms , it will stay at this value even at 250V for perhaps an hour.

Its a void property and been empty for a few months if this helps?

Damp getting in somewhere I think

 

[pc1966]

Look up polarisation index:

Polarisation Index,the better way to IR test.

The insulation resistance and polarization index tests of an electric motor or generator has been regarded as a useful tool in evaluating its windings for build up of dirt or moisture.

electrical-testing-safety.co.uk

 

[buzzlightyear]

The strange part is at 1000 volts

Wow , 1000 volts seams a lot.,whats you thinking electrocution a cow. Lol.

 

[HappyHippyDad]

Look up polarisation index:

Polarisation Index,the better way to IR test.

The insulation resistance and polarization index tests of an electric motor or generator has been regarded as a useful tool in evaluating its windings for build up of dirt or moisture.

electrical-testing-safety.co.uk

And in summary? ?

 

[pc1966]

And in summary? ?

Electricity stretches water.

If your IR is high to begin with, or increases with time under voltage, then probably all is well. IR dropping with time is a bad sign!