Sorry if it sounds like I'm telling it too hard!
, it's the 15 years I spend as a certified biomedical electronics technician in the healthcare field, basically, we were responsible for maintaining all of the hospitals electronic & electrical equipment & a big part of that is the monitoring of the leakage current produced from the electrical patient equipment ( it's known a ground leakage), if you go to your local hospital you'll notice that none of the electrical outlets that are used for patient care equipment are GFI protected. that's for the same reason I stated with the soda machines. They are all however grounded! a typical refrigerator can have as much as 500 miliamps ( 1/2 of an amp) of leakage current on the chassis due to electrical/motor inductance & leakage current tha goes right through the insulation of the wiring. and the best part of this story is it's perfectly normal! ( and by the way, it takes only 10 milliamps of current to stop your heart)
Yes, I know it's probably been working fine for the past few weeks on the GFI, but from my point of view, this means you have (had) a sticky GFI , it should have popped as soon as you fire the machine up! GFI's are required in certain damp / wet electrical hazard areas of a home & business ( in the USA anyway) but technically not required nor recomended by the electrical code on this type of motorized equipment. Yeah , I know it doesn't seem to make sense, but it's for a reason. there are no foolish questions, only fools who don't ask them,
( & people like me who had way to much caffine the other day! sorry if it seem I was barking at you! ) now ... I'd better see a damn good grounded plug & line cord on the machine!