AquaAir Chiller Keeps faulting

My neighbor was having high pressure alarms on his AC.
Replaced the raw water pump cause it was old.
Same alarms.
Disconnected suction hose, plenty of water gushing.
Found the interior of the suction hose would collapse when pump was on.
I do not know the type of hose it was tho.

So if you are changing the pump, maybe change the suction hose too.

Had that same problem on a Hatteras main engine a while back. Would get hot at speed.
Old hose laminate was sucking in and collapsing.
It does happen.

Genset output doesn’t go thru isolation transformers. It only affects voltage anyway, not freq.

Maybe a voltage drop is causing issues but then the system would show a low voltage or power supply error. If freq was dropping during a compressor start you would notice it inside the boat. Plus I am pretty sure that on a boat that size you have freq drive on these chillers.

maybe worth trying to run the system on both generators to see if it faults. Long shot but at this point ...

I run 10 tons of chiller, and I'm set up with two Oberdorfer 1hp centrifugal pumps mounted just below the water line with valve controls and an A/B power switch to allow me to switch over periodically from one pump to the other for all of the obvious reasons. I feed them with a 1.5" dedicated through-hull plumbed to a 2" strainer as overkill for the point of raw water restriction. I keep a handful of strainer baskets aboard and rotate them periodically, like weekly during warm months and monthly when cooler.

Heck, eBay, Grainger, whatever is convenient. The Oberdorfer units are so simple to rebuild and maintain. I just buy parts as needed. Seals, impellers, capacitor, whatever is needed. So simple. And with the spare already in place, I'm not going to be forced into a hot ER to grind through the effort.

Of course, first you need to know the various part numbers.

Some people argue that too much flow means less time for the water to soak the heat in the coil. I guess it s true if you go way over size. As long as you stay with a pump that uses the same size hose it will be fine

As I may have mentioned earlier I like Scott pumps. Very solid and reliable. Depco pump is the best source for any pump or pump motor whether AC, oil change, transfer etc. very helpful and responsive.

we have two Scott pumps on the 116 with valves and a switch as RT suggested. Good set up. Circulation pumps last a lot longer so I m not sure it s worth having two installed. A spare yes obviously... I believe our theee chillers are 60k BTU each.

And also what temperatures are you seeing for the chilled water loop?

sometimes if shore power is iffy I have to shut down one chiller. In the evening it’s fine but during the day , loop temp will creep up to from 39/50 to the high 50s and it s not enough to get the boat cold enough. As soon as I turn that chiller back on loop temp goes back down and the boat cools down right away

on my 53, in winter (Miami) I usually runs just one 36k chiller. Comes May and I need both on during the day.

monitoring loop temp is important. What do you have ?

I try to match pumps up, be them for raw water, circulation, fuel polish, etc to share the same motor. Then it’s a matter of inventorying pump parts and one motor as spares. KISS.

I’m running two fives in series, total of 10. Loop temps run 44 to 54 on #1 and 46 to 56 on #2. Goal is to keep #2 from short cycling and only running when the sun demands it. I’ll alternate units in sequence periodically to keep use balanced.

My setup is also stacked. My pumps are at the bottom. #1 is roughly sitting atop the water line above them. #2 is sitting atop #1, and all raw water ends up at that upper level, splitting and feeding each heat exchanger with cool water, but combining at the same "elevated" point before running downhill and overboard. That split and lift calls for some extra help with the push of water. I wouldn't want to use less pump than I have.

Loose cable, pos or neg, battery switch issue, corrosion.

No way it could affect the chillers.