Insulation resistance

[sparky147]

Hi just finnished installing 5 rcd sockets all rcd sockets are off, started my insulation resistance test, all sockets are conected and its disconected from the fuse board, got 500 m ohms from earth to neutral, 500 m ohms from earth to live, but when i test live to neutral i get a reading of 0.33 m ohms what can be the cause of this?

 

[telectrix]

internal magical resistance bits inside the RCDs. try IR across one individual socket, isolated from yhr others.

 

[malcolmsanford]

there must be either something else plugged into the circuit or the RCD sockets, even when isolated are givng you a reading through the electronics of the circuit.

I have to be honest I don't think I have actually done an IR with an RCD socket connected, I have always disconnected them, as even if I did the test at 250V I would be worried of damaging them. Try and disconnect the sockets, and chocy block the cables and re-test.

 

[telectrix]

it's them little springy bits and coily bits with blobs on the ends

 

[BlueToBits]

Most RCD sockets don't like insulation tests and come with a consumer unit warning sticker. The installer is supposed to disconnect them before testing....