Since I'm not an electrician... here's what I can tell you about how ours works:
(1) We normally have the inverter "off" and only turn in "on" while devices are being used. We normally have the inverter "off" if there is shore power or genset available. Having said that, the inverter can be left on as you plug shore power or run the Onan or both.
(2) The "mw" and "outlets" breakers automatically receive shore, genset, or inverter A/C as available. No need for user intervention.
(3) The green A/C 230V light on ours only comes on when there is A/C from shore or from genset. The inverter has no effect on this light.
(4) At a glance you can know where is A/C coming from or if there is no A/C. We installed the inverter LCD/switch panel a few centimetres below the Onan start/stop switch, and it lights up quite visibly in greenish-yellow anytime the Xantrex is on. So,
(4.1) if shore power: green light on 230V panel;
(4.2) if generator: orange light on Onan switch plus green on 230V panel;
(4.3) if inverter, Xantrex greenish-yellow
All these lights more or less vertically in the port/aft of the main cabin.
All three lights can be on at the same time, if this is the case!
As to the installation itself:
(A) We would have loved to run separate outlets as in Bill's (No. 387), but did not.
(B) On #350, the vertical copper bus bars behind the 230V A/C panel had to be split (sawed off) at the bottom; i.e., "mw" and "outlets" are discontinuous respect to the other breakers. The inverter only supplies power to the "mw" and "outlets" breakers.
(C) We installed an RCD device on the shore power feed before it gets to the inverter.
(D) We installed another RCD device on the load side of the inverter.
(E) There is a little trick in our installation that we used in the U.S. and Canada to power our 50Hz devices while plugged on 60Hz shorepower: turn off the 32A white breaker located on the side of the 230V panel. In this case, 60 Hz shore power ceases to reach the outlets/mw and only clean 50Hz power from the inverter can reach “mw” and “outlets”. Could one mess this up? Sure. But in our 1.5 years in the US/Canada, with this system, we did not kill any 50Hz devices.
(F) You can leave the Xantrex ON while the genset is running; however, eventually the Xantrex will overheat and shut down. You can turn the Xantrex ON immediately after turning off a hot genset and leave it ON indefinitely; no problem. You can leave the Xantrex ON indefinitely as you motor; no problem.
SM2K No. 350
At anchor, Port-Cros (Provence-Alpes-Côte d'Azur)