Thanks, Ken, for your answer and link to ABYC. Since it was my duty, in the 80s, to keep a fleet of inspected vessels in compliance with CG regs I find the concept of automagic (sic) paralleling and synchronizing inverters fascinating, as anyone who has had to synchronize AC gensets by hand would. I believe that the reference (11.5.3.7.) to "individual circuits" not being powered from multiple sources likely was intended to apply to branch or feeder circuits, because combinations of inverters, and combinations of inverters with other sources seem to be permitted: 11.10.2.1.3. On Board AC Generator(s) or Inverter(s) - On board AC generator(s) or inverter(s) to supply the total load as calculated. Total minimum installed KVA for a single phase system is as follows: KVA = Maximum Total Leg Amps. X System Voltage/1000 also: 11.10.2.1.4. Combination of Shore Power Cable(s), On-board Generator(s) and Inverter(s) - A combination of power sources, used simultaneously if the boat circuitry is arranged such that the load connected to each source is isolated from the other in accordance with E-11.5.3.6. Shore power cable(s) plus on-board generator(s) and inverter(s) capacity shall be at least as large as the total electrical load requirements as calculated. Generator(s) and inverters(s) installation and switching shall be as required in E-11.7.3. It's interesting that these rules do not refer to any sort of AC bus other than the "main AC grounding bus" and the "panelboard bus." No reference is made to combinations of multiple sources connected through overcurrent devices to a "bus," which is how it would be done. Also interesting that the ABYC rules appear to be, over time, adopting much of what has been in 46CFR for so long (for inspected vessels). Regards, John "Seahorse" **************Get the Moviefone Toolbar. Showtimes, theaters, movie news & more!(http://pr.atwola.com/promoclk/100000075x1212774565x1200812037/aol?redir=htt p://toolbar.aol.com/moviefone/download.html?ncid=emlcntusdown00000001)