Global Insulation resistance <1MΩ but individual circuits are all > 1MΩ

[HappyHippyDad]

With regards the title is the reason for this because the circuits are all in parallel?

I am talking in relation to a L/N - E test.

If Rt = global resistance for whole CU and R1, R2, R3 = L/N - E resistance for each circuit then am I right with the following:

1/Rt = 1/R1 + 1/R2 + 1/R3

So basically even if the global L/N-E IR test is < 1MΩ, that doesn't automatically mean that an individual circuit is < 1M Ω?

 

[DPG]

Sorry, misunderstood your other post. Yes, if the global check was low, then you would test each circuit individually to prove all were OK.