Very low insulation resistance on ring?

[Des 56]

I

So, I unplugged an extension lead from the problem socket (which had been switched off at the socket anyway) and tested again, and it's back to > 299 Meg. Very odd - socket should have isolated any fault with any connected stuff.

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5-W-W
A possible reason could be that the sockets are single pole and a low insulation reading on the extension cable was being picked up via the neutral of the socket, then clear again when it was unplugged

 

[5-Week-Wonder]

could be that the sockets are single pole and a low insulation reading on the extension cable was being picked up via the neutral of the socket

Blimmin good point. Damn those single pole socket outlets and the people who turn stuff off at the socket.

 

[uksel]

low resistance N-E perhaps ?? these aren't isolated at the S/O

and a Resistance of three hundred and ten thousand ohms (o.31 meg) wouldn't pull enough current to trip an RCD

would be looking at about 0.0007A ?

 

[Johno]

i have had low results before (other than forgetting to unplug appliances) it was the actual socket /spur/switch itself that was the problem. to make sure you could put cables into connectors and retest. if there has been decorators or plasterers you can bet they are to blame.

 

[Jason Smith]

Just installed a max ring, (100 meters) loads sockets but very low max demand, and on doing R1+R2 at the sockets found that one side of a socket was reading 1.0, the other 0.41. o.41 being the expected. One of the phase wires was badly connected in that half of the DSSO. This would of caused havock when testing ir later.So being inexperienced on falt finding ( getting better and better ) I consider that day to be a good onefor experience on DSSO's.

 

[skinback]

Just installed a max ring, (100 meters) loads sockets but very low max demand, and on doing R1+R2 at the sockets found that one side of a socket was reading 1.0, the other 0.41. o.41 being the expected. One of the phase wires was badly connected in that half of the DSSO. This would of caused havock when testing ir later.So being inexperienced on falt finding ( getting better and better ) I consider that day to be a good onefor experience on DSSO's.

What is DSSO's ????