IR readings

[still learning.]

hi, my friend had an conservatory built 20 years ago and there are two sockets in it and they are wired into the main ring via an existing socket in the house, recently every now and then if he used these sockets the RCD would trip so i have disconected from the main ring and IR tested the cable to the conservatory sockets, the reults i got are
live - neutral >1000m ohms ( and a tick)
neutral - earth >1000m ohms (and a tick)
live - earth 520m ohms (and a tick)

I have a metrel 3002 and a tick appears after the reading if it complies but because of the lower reading between live and earth can I saftely assume that there is a problem there.

 

[Darkwood]

The readings you are getting 520M-ohms is can also be worded 520Million ohms and this reading is a very good i would query what hes using in the sockets to see if the tripping is caused by the same item.

 

[Deleted member 9648]

Technically any reading above 1 meg is ok although it is recommended to be above 2 meg on an individual circuit.....in pratice readings as low as 0.5 megs rarely cause tripping problems,only below that are you likely to get nuisance tripping.........your readings are way over anything to worry about.

 

[Amp David]

If using a Megger 1552 you would of seen >299 for all tests so wouldn't of even known.

 

[still learning.]

thanks, but am still wondering just out of curiosity why the live - earth reading is half that of neutral - earth and live - neutral, I thought they should all be the same?

 

[telectrix]

could just be you got a firmer connection on the lower reading. at these high values of resistance, even breathing on the croc clips can affect the reading

 

[robswainelect]

Hi,
Can't see any problems with those readings!