I have some low voltage landscape lights that are pluged into a gfi protected outlet, when it rains the gfi trips would rain splashing up on the bottom of the transformer cause the gfi to trip or not.

Possible. Weatherproof while in-use cover?? Condition of 120 volt cord/cap/connections? Correct cord connector on xfr entry??

yes in-use cover.factory cord looks ok.wires on transformer look ok. could water splashing on low voltage side of transformer cause the gfi to trip,the wire from the transformer to the lights is 10/2 low voltage wire(2 conductor no ground)

Is there a current path between the 120 VAC neutral and the secondary side?

Larry C

You could try disconnecting the low voltage wires from the transformer, and see if it still trips. I have had several GFI's that were bad, especially if you've had thunderstorms in your area. Try also disconnecting the transformer from the outlet, and that will narrow it down more. Steve...