How much power is Neptune slated to pull? Is it beyond anything a typical US household/apartment AC outlet could feed?
I think it will be like this:
If you connect the Neptune to it's OWN 20amp circuit, with nothing else, you should be fine.
Whatever you do, don't put it on the same circuit as something like a microwave, or toaster, or anything that draws significant wattage. Make sure it's on a 20amp breaker minimum.
When you estimate a 20A circuit, you mean on a 110V line, yes? European 230V @ 16A would give 3680W, which should probably hold if
kendog77's estimate of 3000W power draw is anywhere near what we will get.
I really hope that it will draw less than 3000W to be able to have it along other things on a slightly loaded circuit.