twistedtree,
Had a look at your blog and really enjoyed the Watermakers and Shore Power Conversion sections. I want to put a watermaker on 'my' boat and the Spectra is now on my short list.
Glad you found the blog helpful/enjoyable.
Is your charging system set up so that both engine alternators can dump into your house bank?
Yes and No. The big alternator (190A) goes to the house bank, and the smaller on (85A) goes to the Starter bank, so on first blush they are separate. However there are parallel switches that allow the banks to be combined which would also combine the charge current. I'm contemplating rewiring so both alternators charge the house bank, and using an electronic charger to top up the start bank, but it's only a thought at this point. I just expect the start bank to recharge quickly leaving me with an underutilized 85A alternator.
What other house bank recharge system(s) do you have?
The house bank can also be charged via shore power or generator power using dual Outback inverters in charge mode, plus a 100A Victron charger. The total is 260A. Also, in a pinch, the house bank could be charged via the wing or generator alternators, again by paralleling battery banks.
Do you carry alot of 24v spares?
I'm sorting through spares now and have list that's many pages long. I'm doing it in two waves. This first will be for roughly our first year of cruising where we won't be anywhere more remote than Alaska. Then the second wave will be before we cross the Pacific and will add a bunch more parts.
As for 24V spares, there actually aren't that many now that you mention it. On my boat a lot of things are AC powered where on a smaller boat (like our Grand Banks) then are DC powered. Galley, head, engine room, laz, etc. fans are all AC and I am stocking one of each type used (3 types in total). Refrigeration is all AC as well as all the water pumping. I think the big 24DC items, other than the various engine controls, are lights and electronics. I'm carrying spare bulbs and the electronics are set up to be either redundant or I carry a spare, but it's mostly redundant. But now I'll need to go through the boat with this in mind and check, so I'm glad you asked.
If your refrigeration is 24v, is it hard to come by?
Are other 24v appliances you might have hard to come by?
No, refrigeration is all AC.
The water maker is a significant DC appliance, and one that's important to keep running. I'll carry a set of spares, but haven't made that list yet.
Interestingly, one of the boats biggest vulnerability is the 12V DC system that is derived from the 24V system. It's just as you contemplate for yourself. The 12V system powers all the radios, the navigation computer, the horn, the propane control, and the NMEA 2000 bus. If I lose 12V, I'm screwed. Needless to say, I'm carrying a spare power converter.