Pool light transformer keeps tripping gfic breaker

[Patwano]

New install of 12v nicheless 20w pool light connected to 100 watt listed transformer, 20 amp Eaton br gfic breaker,,,,breaker trips whenever switch is turned on even with no load on transformer (light disconnected) ,,, transformer and breaker are new,,never ran into this before with square d breakers,,,,bad transformer or bad breaker??

 

[Sierrasparky]

place a different load on the light circuit in place of the transformer. If it trips it is a problem with the wiring . otherwise it is the transformer.

 

[Patwano]

Already tried that,,all was good

 

[LarryFine]

Try it with the primary disconnected at the transformer, and then try swapping the transformer primary conductors. Also, try the transformer on another circuit.

 

[Little Bill]

Already tried that,,all was good

What do you mean by "all was good"?
If you're saying the breaker held with another load then you've solved your problem, change the transformer.

 

[Patwano]

Try it with the primary disconnected at the transformer, and then try swapping the transformer primary conductors. Also, try the transformer on another circuit.

Tried one and two,,haven't tried the third yet

 

[cpinetree]

Why is the transformer on A GFCI? It does not need to be.

 

[kwired]

Why is the transformer on A GFCI? It does not need to be.

Might not need to be - sounds like it has problems though, it shouldn't leak enough current to trip a GFCI.