LED Panel Strange problem..

[Alex G]

So a long story short, someone I work with said they had a small 'Tingle' off a Lumineux LED panel. We took a couple down that we recently installed, and plugged them into a safe tester to check if there was any voltage flowing through them. Oddly enough, we read 90-95V AC to earth, straight off the metal back of the panel. This is strange, as the Driver's output is only 38v DC. This was the same for all the fittings we tested. I spoke to Lumineux, but the guy thought I was crazy! Even if they were all faulty (they are all working fine) where is the 90VAC coming from?

Any Ideas?

 

[shaun1]

Check the case and PSU are properly earthed. Switch mode PSUs usually have a capacitor between live and earth which provides part of an EMF filter I believe. This causes some leakage to earth. If the PSU doesn't have a good connection to earth this will appear as a voltage on any exposed metal parts.

 

[Alex G]

Thanks for the reply... The LED Driver is double insulated and does not have an earth... The driver is not giving out enough voltage to cause the back panel to have 90V even if the fitting wasn't earthed properly. These are all plug and play so there isn't an option to earth the fitting, unless I did it to the grid it's placed on. but still... where is the 90V coming from

 

[shaun1]

Try measuring between the output terminals of the driver and earth. I think class 2 PSUs have the input and output coupled by a capacitor, again as a suppressor of EMI.