I had a 4ft 36w flossy tube up in the loft that i wanted to replace with a 5ft 58w one that i bought a while ago but never got round to putting up. I put the light up when i boarded the loft out about 9 or 10 years ago when we moved in and it was a right mess to be honest with you!
It was all wired in 2 core flex so no earth, luckily when i switched the light off at the switch in the loft i checked the flex with my volt stick as i had ran the live straight through in the back box and switched the neutral
obviously with no earth at the fitting i would have checked for voltage between live and Neutral got nothing with the switch being off then probably got a belt when i took the fitting off! (A good lesson in safe isolation that i wont forget, i went downstairs and flicked the breaker off!)
Anyway re-did it all properly in 1.5 t+e with the 5ft Lamp under the ridge and the 4ft over by the loft hatch, checked contunuity of my earths at both fittings to the ceiling rose i had taken my feed from but i was a bit unsure about the IR tests...
At college we would remove the lamp then IR test at 500v E to L, E to N then N to L however with this being a flourescent fitting i didnt want to damage the ballasts so i just tested 240V and got readings of >99Mohms with the switch on and off.
I know i could have disconnected the fittings but it got me thinking as the factory i work in is has flossy tubes mounted about 40 foot up in the air and there are about 5 or 6 spread out on a circuit so it would be a right pain having to disconnect them all to do an IR test.
Ive read since that you can join L to N and test this against the Earth to avoid damaging a load but would you still do this at 250v or 500v?
A bit long winded but its a background to what im stuck with and why!
It was all wired in 2 core flex so no earth, luckily when i switched the light off at the switch in the loft i checked the flex with my volt stick as i had ran the live straight through in the back box and switched the neutral
obviously with no earth at the fitting i would have checked for voltage between live and Neutral got nothing with the switch being off then probably got a belt when i took the fitting off! (A good lesson in safe isolation that i wont forget, i went downstairs and flicked the breaker off!)Anyway re-did it all properly in 1.5 t+e with the 5ft Lamp under the ridge and the 4ft over by the loft hatch, checked contunuity of my earths at both fittings to the ceiling rose i had taken my feed from but i was a bit unsure about the IR tests...
At college we would remove the lamp then IR test at 500v E to L, E to N then N to L however with this being a flourescent fitting i didnt want to damage the ballasts so i just tested 240V and got readings of >99Mohms with the switch on and off.
I know i could have disconnected the fittings but it got me thinking as the factory i work in is has flossy tubes mounted about 40 foot up in the air and there are about 5 or 6 spread out on a circuit so it would be a right pain having to disconnect them all to do an IR test.
Ive read since that you can join L to N and test this against the Earth to avoid damaging a load but would you still do this at 250v or 500v?
A bit long winded but its a background to what im stuck with and why!
