Tips for doing insulation resistance testing building with LED lights

[Tradie]

Does anyone carry out insulation resistance tests on occupied buildings?

Any tips for how you do it without disconnecting every single LED/electronic device?

Maybe use the 250 VAC setting, like we do to test those red surge protection plugs.

I see the new fluke multi function tester can test surge arrestors, at R80 000 I dont think I will be upgrading my current fluke multi function tester.

[Dave A]

I've supplied my peeps with a UT251A clamp leakage meter. Keep it away from EMF generators (such as relays) and it seems to give a pretty good indication of current loss down to .001 mA.
If the voltage is 230V - get a reading under .230 mA and it's a pass...

[GCE]

There is a clause that covers existing installations

Sans 1142-1 ed.3.2
8.6.8 Insulation resistance
NOTE 1 Before power is connected to any new or altered circuit, the test for insulation
resistance should be carried out to ensure there is no short-circuit or high impedance
faults in the installation, and that it is safe to energize.
NOTE 2 In the case of existing installations where the power may not be switched off
from certain circuits in order to carry out this test, the fact that the circuits are subject to
the supply voltage can be regarded as evident that the insulation resistance is
compliant.

[Tradie]

Just to update as to why I started this thread, I agree the sans reg, hiring scaffolding or lifts to disconnect lighting in an 8 m high factory, cost money and is it really worth the cost and time ?

However, I have a situation where right now the power is switched on and everything works great, until there is a bit of rain, then BOOOM, the inverter output breaker trips, not the lighting 10 amp lighting circuit, the 32 amp inverter output breaker, which seems a bit strange, I have also had breaker downstream trip, but not the breaker in the room.

This is where the challenge begins, live to earth and neutral to earth insulation resistance tests no problem, but I can't test live to neutral, without disconnecting every single light, and boy there are a lot of them. The other challenge, would a 250 V IR test detect the fault, if the breaker is not tripping, would you need 500 or 1000 v to create the arc?