What are the possible causes of low IR readings at 500VDC?

Bizron · Jul 2, 2020

Kitchen RFC 2.5 T+E - IR=>200MOhms at 250VDC L&N to E but 0.34MOhms at 500VDC L&N to E.
I suspect damp/corrosion in sockets, what do you reckon?
All socket switches opened including SFCU to cooker hood, F/F, D/W and W/M.

radiohead · Jul 2, 2020

There's likely to be a surge protected lead plugged in somewhere, that reading is absolutely bang on for a surge lead

westward10 · Jul 2, 2020

Damp issues would be evident at 250v, as above surge protected lead or surge protection within an appliance. It could be an rcd spur or socket however these normally indicate low readings even at 250v.

Baddegg · Jul 2, 2020

Are you sure you’ve unplugged everything??

diditrain · Jul 2, 2020

Don’t think he went down that route, due to the test method used.

Gary latto · Jul 2, 2020

Interesting to know effects of a surge protection plugged in when testing cheers ?

PEG · Jul 2, 2020

Don't discount an accessory or wired-in item,which has an internal surge protection device.

Bizron · Jul 14, 2020

Thanks for replies, I am trying to get an idea of actual readings for different accessories/appliances that can point me in the correct direction of what to hunt for. Today I was in a hoarders house with access to every socket impossible, got low readings LN&E, fridges/freezers always seem to have some leakage that will skew readings.