I would agree with John:
Best suggestion I can make is- call the heat pump maker and ask!
It kind of makes me wonder about the legality, or indeed the safety factor of running a piece of equipment like this, where a winding may short to ground.
This is amplified by the fact that people will be immersed in the water supplied by a unit like this.
One other recommendation I would make is ask your Inspector or AHJ about this one.
If there are GFCI's now that can overcome these Compressor leaksge currents, that would be a great leap forward.
Nuisance tripping is usually the first reason why most safety systems are either bypassed or removed completely.
Let's face it, these days if you're not young, you're old - Red Green