T5's tripping GFCI?

[sondaar]

Tom,

I have a 48" Constellation that trips the GFCI when the 3rd switch is turned on. Is this fixture not compatable with GFCI receptacle because of harmonics in the ballests? I've tried turning on switches in different combinations and it will hold any two combinations but as soon as a 3rd switch is turned on it trips the GFCI. I've also ran it to a regular receptacle and it runs like a champ!

Thanks
Mike

[Aquactinics]

Mike,

Lighting ballasts have what's called "leakage current" measured in the milliamps. GFCI circuits measure the difference between the incoming and outgoing current. When the difference is above the threshold it trips. As more ballasts are turned on the "leakage current" adds ups to the point it goes above the threshold of the GFCI and trips it. This is why when you have two switches on it is still below the threshold, but three goes over. Most GFCI are not designed to work with electrical devices such as lighting ballasts. There are a few GFCI plugs out there that have a high threshold for the leakage current. Otherwise your best bet is to use a non-GFCI circuit and make sure you have a drip loop in the power cord. Just to let you know, the fixture is fully grounded.

If you have any other questions please feel free to contact me.

Thank you,

Tom
Aquactinics
203-234-9286

[sondaar]

Thanks Tom,

Thats what I was thinking but didn't know exactly how to explain it or describe it like you did! Love the fixture, cont wait to put some livestock in the tank!

Thanks again,
Mike