On Frigoboat systems with multiple compressors, the pump interface is used. This also divides 24v to 12v to power the fridges. It has been explained to me that Frigoboat sells you a 24v pump and runs it at 12v. Theoretically it should be continuous duty at that point as it's running slower and cooler. This is not the case for the vast majority of us, it seems. It would be better if it coordinated compressor run times, but alas that's not the case.
Soraya - I purchased the Marco pump as my FIFTH one onboard. I still have 3 total Frigoboat pumps remaining so I will use all of those and then switch over to the Marco. Is the noise annoying? As noted, mine runs 80% duty cycle or so.
Stefan wrote on another post (https://amelyachtowners.groups.io/g/main/topic/pump/69698758?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,69698758) that he's used a magnetic pump that lasted a really long time. I looked at the PDF and it seems Y-1638-MM would work great if you set it to run about 4-6 liters per minute.
It seems to draw very little power at that level and it appears to have a large head capacity. Someone smarter than me needs to figure out if that means it can self prime and push water through the circuit connecting all 3 compressors? It's 24v, which would mean you'd probably have to either just run it on the 12v that comes out of the Frigoboat pump interface or install a relay into the system and run it on 24v. Any engineer want to give an opinion on this solution?
FYI Frigoboat specifically states the water hoses should run parallel from the pump to the individual compressors and our A54 has them run sequentially. That probably just means after the first fridge, each subsequent fridge is getting slightly warmer water.
I believe the new Amels have keel cooled fridges. I believe that's a better solution but I try not to intentionally put more holes in the hull, so I won't be retrofitting in the middle of our circumnavigation!
Finally, my A54 is plumbed to use fresh water to cool the fridges. We have no growth issues and pumps still last 6 months. So that won't solve the short pump life problem. I tend to agree that the insulation is crap. On the under settee freezer, the items that are far from the evaporator "cage" often thaw out, even with the freezer on max. I have added supplemental sealing on the lid, which helps, but the problem still exists.
The FW water tank temp never gets noticeably warmer but we also never drop below 150 liters. As you know, it's in the keel, but GRP is not a fantastic thermal conductor, so there is some the temp will always be a bit higher than surrounding water, imo. There has been some discussion of lead solder on the copper piping. I am not sure if this is true or not, but to be safe we only cook and drink water from the Seagull filter. I have used their portable version while backcountry camping and once found myself at a lake full of cow poop. We had no choice but to use the water and I am still alive today. In any event, most brass and copper fittings in homes have lead in them.
2007 A54 #69