IR on em lighting

sellers · Feb 24, 2010

I'm getting 0.11meg on live conductors to earth on a circuit of 25 em lights. I take it this is due to the battery packs and pcb's? Am I right? How would you get round this for a periodic? Thanks

Evans Electric · Feb 24, 2010

Its much the same with fluorescent fittings , IR readings will be all over the place, I do'nt know what the "official" advice is . As far as I know there is no point trying to get readings unless you disconnect every fitting, and lets face it, who's going to do that.

Revved Up Sparky · Feb 24, 2010

I'm getting 0.11meg on live conductors to earth on a circuit of 25 em lights. I take it this is due to the battery packs and pcb's? Am I right? How would you get round this for a periodic? Thanks

As EE rightly said, you need to disconnect all loads to get accurate readings. If it is impractical to do this then I would write a note in the limitations section saying something along the lines of "impractical to disconnect each emergency light fitting therefore 500v IR test omitted".

Sometimes when I am doing PIR's, I find that emergency lights have got individual keyswitches, in which case I simply switch them out - although the neutral will still be connected unless the keyswitch is double pole (the switchwires will of course not be tested so that would need to be recorded as a limitation.)

Occasionally I will do a PIR on a lighting circuit and find that the fittings are all on KLIK connectors - so if it is practicable to unplug each one then I will do that.

The bottom line - in my experience - is that you don't really want to be spending much more than 40 minutes on each circuit (unless your client specifically asks you to investigate more thoroughly) and so it might just be best to either note a limitation or make an observation with a (3) , ie 0.11meg reading requires further investigation. Then you are covered.

sellers · Feb 24, 2010

Cheers guys, top advice.

With regards to fluorescents affecting IR results is this more of a case with HFfittings? The place was laced with switched starts their results were perfect.