What is going here then?

newtotest · Oct 10, 2018

So i am doing a new wiring job and all my cable is testing out fine. However the customer wants to put 2nd hand brass chandaliers up which i said could be an issue on IR tests if they are really old or damaged. Sure enough i have come to fit one and it tested at 0.96M live to neg. So i opened it up and the wiring appears to be either fairly new (blue and brown) or its been rewired. Either way each of the 15 arms is wired in singles back to the body where is was all together in connector strip. So i disconnected it all and metered the arms individually. Most tested around 3 to 4M. I removed one arm completely and it tested the same. I stripped out the wiring and pulled new in and reconnected the lamp holder. Still it was 3 to 4 M . So i removed the lamp holder and tested the new wires which were indeed fine. So i tested the lamp holder which showed the 4 M . I dissassembled the lamp holder so that it was litteraly the peice of bakerlite or plastic with two spring connections and it still tested at 4M between the terminals. I have wiped it washed it and dryed it and it doesnt change. In fact if i take the terminals off the plastic from edge to edge reads about 50M???

Any ideas whats happening here? Whatever is happening is happening to all the arms to varying degrees. The bit i stripped it down to is in the pic.

I am stummped as to how there is any connection on this part. Meter is testing other light fittings and they are reading well over 300M. It just seems to be these large 15 arm things.

telectrix · Oct 10, 2018

at 4 Megoms. it's perfectly acceptable crack on.

MDJ · Oct 10, 2018

newtotest said:
So i am doing a new wiring jib

JIB? very confused here

newtotest · Oct 10, 2018

Its not 4M when all the arms are connected together is the issue. Also would like to understand why this is happening it makes no sense.

Lucien Nunes · Oct 10, 2018

Either there is a deposit on the surface of the plastic insulator of the lampholders that your washing and drying did not remove, or the plastic is of inferior or degraded material that is conductive all the way through. Perhaps the surface is slightly porous and moisture has penetrated if they have been stored in a damp place. Try baking one out, or running a lamp in it for 24 hours, and see how it measures.