It turns out that Sarkis was working on a boat equipped with a Seakeeper Gyro stabilizer as well as an ELCI, something I’ve often written about here. His findings need to be need to be shared before anyone else gets driven nuts over it. It turns out that when the Seakeeper is turned on it consistently trips the installed ELCI device for the shore power service. (You can learn more about ELCI devices here.)
After much back and forth he was able to establish positively that the unit, which has both AC and DC inputs on the particular boat he was working on does create a ground fault in the AC system. About the only answer the engineers at Seakeeper were able to give him was that “the unit complies with all applicable industry standards.” OK, that may be well and good, but it seems it won’t work on a boat equipped to comply with ABYC E-11 Standard.
Fortunately the boat in question is large enough so that installation of an isolation transformer for the shore power system is actually a practical choice and will eliminate the need for dealing with an ELCI. This is new news for a lot of techs out there which is why I’m sharing this information with you all.
The good news is that this is probably only going to impact larger powerboats that in general are more likely to have an isolation transformer installed in their shorepower system, so I don’t expect this to be a wholesale problem. Good to know anyhow for anyone doing marine electrical work at a professional level.