Hey Paul

For insulation resistance readings between conductors or earth you should get 200MOhm's or higher, 0.5MOhms does comply altho this requires further investigation.

Make sure you do the tests on a disconected circuit or you will get false readings.

Quote:


Correct testing is between any conductor and earth, 500MOhms is a normal reading, you can test all circuits together but you may get a lower reading and this would require spliting up all the circuits and testing one by one to ensure they all have acceptable readings.

No problem Paul, just make sure theres no 'holes' in the cables, and that you can test seperatly or as a 'whole'  

also

For Circuits operating at 230V testing is at 500V

For Circuit's operating at SELV testing should be at 250V