Short Circuit When Emergency Lights Are Connected

normanton · May 17, 2018

I've come across a fault at work. Fuse keeps blowing when they put it in. I haven't tested for a while, and so am pretty sure I'm missing some basic steps with the fault finding process.
Small room. 1 emergency fluorescent light fitting, 1 bulkhead emergency fitting.
Fluorescent is plugged into a click on the ceiling. Live and Neutral have been wired from this click.
Dead shot L-E.
Unplugged click. d/c bulkhead. Fault clear.
IR test on disconnected cables at bulkhead - >999.
As soon as I connect either fitting, dead short L-E.
What am I missing?!?!
I'm ready for all the abuse.... Come at me...

Darkwood · May 17, 2018

It would point to incorrectly wired click unit IE Live is in the earth terminal etc or the click is internally faulty and the physical action of plugging into it creates the fault... this is going only on the info' you provided, if you have missed any tests or have not been forthwith with all the information then we may be going down the wrong path with my suggestion.

Pete999 · May 17, 2018

normanton said:
I've come across a fault at work. Fuse keeps blowing when they put it in. I haven't tested for a while, and so am pretty sure I'm missing some basic steps with the fault finding process.
Small room. 1 emergency fluorescent light fitting, 1 bulkhead emergency fitting.
Fluorescent is plugged into a click on the ceiling. Live and Neutral have been wired from this click.
Dead shot L-E.
Unplugged click. d/c bulkhead. Fault clear.
IR test on disconnected cables at bulkhead - >999.
As soon as I connect either fitting, dead short L-E.
What am I missing?!?!
I'm ready for all the abuse.... Come at me...

Been doing the bang test a few times then? sounds as though the EM fittings have developed a fault possibly by subjecting them to being re-energised under faut conditions, maybe? Is this a new installation? if yes could be you have the klick plugs wired up wrong.

normanton · May 17, 2018

Existing installation. I haven't put the fuse back in personally, but that's not to say somebody hasn't tried before me. When I d/c the L&N that goes from the click to the bulkhead the fault cleared. It all points towards the bulkhead. Funny, because they I had a carbon copy of this fault a few weeks back, and the only way the fault cleared was when I d/c the neutral going from an existing fitting to a new bulkhead. They've basically borrowed neutrals from existing fittings and what not to get these bulkhead light fittings on. All seems a bit heath robinson to me.