Hi!

I recently replace an existing 30AMP 2 Pole with a 30AMP 2 Pole GFCI on my main panel. This breaker services my pool equipment - which are mostly 240 but also have some 120 lights and misc equip. I noticed that the 2 hot conductors are either #8 or #10 copper but the neutral (white) is #12. Is this normal? Is there a chance that it can overheat? Can it effect the voltage since the drop is about 100 feet? If necessary what can be done to remedy the situation other than pulling a new neutral conductor?