Now this post has no kidding around on my part. The largest maker of hot tubs has plenty of models that do not use a neutral conductor. And there is no place in the control box to land one. They are 240 volt units not 120/240. You will need to land a neutral at the disco from the source in order for the proper function of the gfi 2 pole breaker but it is clearly stated in the installation booklet to not install a neutral conductor from the disco out to the tub.
