Lighting fault

[tommy.dale]

H guys I wonder if anyone could shed some light on a fault that I have just attended, I fitted some fire rated led dim able lights in a pub, about 60 of them.
there was about 6 led downlights previously fitted that was working (fitted before I took job on) and was working since I done my bits upto 3 weeks ago, anyway i have gone back to do some more work and these 6 lights aren't working.....

my fluke t51000 isn't showing any voltage, I seperate the t&e fromthe lights and find the incoming feed from board which I get 230v on, perfect right?
i add the links in to daisy chain the lights and the voltage disappears completely yet I separate the t and e and voltage is there again,

when I attach the feed by itself to one of the fittings it comes on but not when any other Load is added.
there was also 2 fittings with the n-CPC reversed yet I saw these working??

anyone experienced this and could help me out before I rip everything out tomorrow?

tom

 

[tony mc]

When you connect up the other lights what are you missing at the next light that is not working a line or neutral. It sounds like a connection issue after the first light. Neutral CPC reversed will still have the light working think about it but it is a fault which needs sorting. If a RCD was on the cct it would trip.

 

[tommy.dale]

I only spent 15 minutes there I'm going back tomorrow, no rcd fitted, gna be a pain in the arse to pull these lights down and it's a solid oak cladding which is at least

- - - Updated - - -

With at least a inch and half of depth, but I'm just gna have to take all fittings down..

at the next light there wasn't any voltage at all so might need re wiring

 

[telectrix]

if you are seeing volts with loads disconeected, sounds like a bad connection at a fitting. start at the first one and work through them. the fault should be close to the start point. make sure there's no JBs fitted to the original circuit.

 

[GLENNSPARK]

Yep Tel....
a classic this...
when no load there shows what appears to be a healthy voltage present...
but as soon as its asked to push some current....lol...

 

[SJD]

I seperate the t&e from the lights and find the incoming feed from board which I get 230v on, perfect right?

Did you make any Zs measurement at this incoming feed?

 

[Guitarist]

Did you make any Zs measurement at this incoming feed?

I'm assuming you carried out Zs at each fitting too before you handed it all back? Was it ok then?

 

[telectrix]

but a Zs would not identify a loose neutral. and sod's law says that it's usually the neutral that has the poor connection.

 

[tommy.dale]

Sorry guys for the late reply, luckily these 6 lights are on its own mcb so locked it off and ill be going back tomorrow, I love working Sundays!!!!!

 

[Guitarist]

but a Zs would not identify a loose neutral. and sod's law says that it's usually the neutral that has the poor connection.

Agree tel, was just trying to determine exactly what the op has tested for.

 

[telectrix]

so do i. no traffic jams, and i get to miss the omnibus editions of emmeroids, which 'er indoors has to watch although she's seen 'em all week.

 

[tony mc]

I would guess a IR test was missed due to the CPC's & neutrals cross connected at some of the fittings !

 

[Octopus]

Sorry guys for the late reply, luckily these 6 lights are on its own mcb so locked it off and ill be going back tomorrow, I love working Sundays!!!!!

Time to get your wander lead out and do dead test continuity tests from the board to the first light then!

 

[GLENNSPARK]

but a Zs would not identify a loose neutral. and sod's law says that it's usually the neutral that has the poor connection.

but a Zpn would though....

 

[telectrix]

or a 1000V IR test and look for sparks