gfi trips

[bobbopulaus]

i installed a gfi in the bathroom.it works fine until i hook it up to the gfi,then it trips.i changed the light fixture and grounded it.it is wired correctly
i think the problem is in the wires that run to light fixture.is there a meter i can use to see ifim losing voltage somewhere?or is there another test i can perform to find my bad wires?

[HayZee518]

why do you need a gfi on a bathroom light?

[leone184]

I assume you mean you were hooking up a light fixture to the GFI. I know you can string other outlets from a GFI, but I'm not sure about a light fixture. I can see how it might cause a fluctuation that will trip the GFI, especially a flouresent. Does it trip as soon as it's connected, or only after you switch it on?

[bobbopulaus]

Thanks Hay Zee And Leone.the Light Fixture Is Metal Which Touches The Bathroom Mirror Frame.thats Why I Thought It Would Be Best To Have A Gfi Hookup.its A 6 Light Incandescent Fixture.

[HayZee518]

A gfci is meant for protection of personnel against fault currents. say if a hair dryer has a metal shell or metal parts that could likely be energized if the motor inside shorts to the frame. It wouldn't be enough to trip the breaker but the metal would be at 120 volt potential. A body in direct contact with the metal and a cold or hot water pipe through the faucet would create a hazard and a gfci would trip preventing a shock. What are the chances that a light fixture would accidently develop a ground fault? The shell of the lamp is connected to the neutral. The center contact to the bulb has adequate clearance given the 120 voltage. The bulb would have to blow up and the filament would have to touch the shell but most filaments just burn up creating an open circuit for that lampholder. If there is an integral 120 receptacle on the mirror/light combo, then a gfci would be in order.

[bobbopulaus]

thanks hay zee.that makes sense.so can i pig tail the hot wire,one hot to line side of gfci and one hot to light switch.thanks again,your a great help and much appreciated