I'll try to make this as short as possible. Bought a house with a hottub that was hooked up and working fine without GFCI breakers (inspector did not catch it) I installed recommended 30 and 20 amp 220 2 pole GFCI breakers in the panel which happens to be right next to the hot tub. 20amp keeps tripping instantly when I turn it on. It appears to be wired correctly a white and black load and a uninsulated neutral (12/2??) from heater side of tub.Call a electrician. I get home about the time he's finishing up. Says he fixed it and its working fine now. said something about the neutrals and grounds weren't hooked up right. Pay him and thank him. I pulled the panel cover back off to see what he did differently. He apparently unhooked the neutral from the GFCI comming from the tub and loosely wrapped it around another ground wire in the box. I can not see how the GFCI will detect a fault like that.