Low IR on ring final.

[entech]

Hi chaps,

Been searching thru posts but to no avail. I have one ring final with IR of approx 0.98 Mohm L-N , 1.48 Mohm L-E on 500v. I later found one appliance plugged in (dishwasher) but didnt have time to re test. The fcu above worktop was switched off for this applince but it was still connected via flex,plug top, and unswitched single socket. Could this be the cause off poss low IR reading?? One other thing I thought it could be is CH digital controller. Other than that I guess its a re-wire.

Any help be appreciated.

Cheers

 

[Deleted member 26818]

I think I would re-test either with L&N connected together to E, or disconnect all appliances that might affect the readings before re-wiring.

 

[entech]

Thanks for reply, yes that is what ill do later today. Is is poss that if an appliance is still plugged in bu it is switched off
(FCU) could it give a low/incorrect reading? I cant see how as the live feed is broke.

 

[Des 56]

ther than that I guess its a re-wire.

Until the problem is shown to be the installation and not the testing procedure,thats a bit of a drastic conclusion

Most are double pole.but if yours was single pole,the neutral still being connected will then include the appliance

 

[Deleted member 26818]

Yes if the FCU is switched off, then you should get a good reading, at least between L&N.
However you mentioned something about a CH digital controler?

 

[telectrix]

i'd go along with spinlondon here. L/N shorted and test to E.

 

[ezzzekiel]

cant see how (in majority of cases) linking l/n alters the test reading often comes back with similar result until item is disconnected?

 

[andybeach]

If everything is disconnected my guess would be a deteriorating socket somewhere. Try disconnecting the sockets one at a time and seperating the wires then rechecking IR.


It may not be the case here, but its a mistake I made rushing one day. Make sure the neutral is disconnected in the consumer unit or you could be measuring a N-E fault in a different circuit.

 

[daiplayer]

Test between live conductors connected together and earth , should show same result if not lower ( parrallell paths ) ,

However it is a pass ......so there isnt a problem. ???

 

[brucelee]

Hi mate 0.98 is not a pass its a fail as its below 1M/ohm and the L-E 1.48 requires further investigation to locate the reason for the low Ir as its below 2M/ohm

 

[daiplayer]

Hi mate 0.98 is not a pass its a fail as its below 1M/ohm and the L-E 1.48 requires further investigation to locate the reason for the low Ir as its below 2M/ohm

duuuuuh...dunno what figures i was reading , lol....long day of maths , :-/

 

[sparkinlee]

I had one of these the other day, and it's worth making sure the appliances are unplugged, not just switched off at the sockets - the fault I found turned out to be in a socket, but only with the socket turned on! I was about to condemn the washing machine, when I just thought to do a test with the socket ON but with nothing plugged in...

 

[ezzzekiel]

low readings can be picked up and crossed over, always better to get everything disconnected