AC Pump Trips Main Breaker

Oberdorfer pump makes their own bronze assemblies. The electric motor is the flavor of the month brand (GE, Century, Dayton, etc).
These electric motors are all usually open 56J, air cooled frames. Life span is subject to the environment.
You can see in this pump's installation (post #2), it it amazing it lasted this long, IMO.
But I have witnessed way worse.

Then, the pump's issues; as all brands do, the metal impeller and body wears away and the mechanical shaft seal will leak without warning.
Again, the environment; more silt-shorter life.

They should last much longer than a couple of years but when they fail it s usually not the motor but the head and the problem is either galvanic corrosion or erosion.

I was told that accelerated erosion is usually caused undersized hoses causing cavitation.

It s not just Oberdorfers (or the cruisair labeled Os) but pretty much any pump with bronze impeller and housing. Any of these will eventually erode resulting in weaker flow or pin holes in the housing. I v head this happen on a bigger Scott pump a few years ago.

Personally I prefer March pumps. The plastic wet head last much longer and are easy to swap. And leaks thanks to the magnetic drive.

Why? Mine lasted 25 years, it was a March though, replaced with another March .

180 to 200 GPH per ton of AC (12Kbtu)

I make my own using Nylon 3/4" Ts and 90s. Nylon or Marlon 3/4" male pipe to 5/8" hose barb.
Grey short pipe nipples and reducer/adapter from the pump.
Lots of teflon tape. Just snug to not leak, not over tightened.
Keep it composite and never worry about it again.

These guys have excellent prices on March pump

. https://flagshipmarine.com/pumps/

I ve been using a 1620 gph TE-5.5C-MD For 5 years now for my two 36k chillers. It runs 24/7/365

I have bought a 3100 GPH TE-7P-MD Which we re going to install on the 110 this winter to replace one of the Scotts which are about 4 or 5 years old. We run the chillers on one pump with the second one on stand by. March has even bigger models

Lets see; all 3 condensing stations are there in the picture?
Top condensing station raw water inlet 5 feet max over the hull water inlet?

Pulse a few bends in the hose and fittings, lets guess the pump is pushing a 6 foot head.
You require approx 700 GPH for 44Kbtu.

The LC-5C-MD will push 840 GPH at 6 feet, 715 GPH at 12 feet.

IMO, good choice.

I would further say, your previous pump was moving to much water and not letting the condensing coils work to well.
Just the 104M is a common and more readily stocked (cost reduced?) model.
I have 3 of them on my boat.
Yes, I am over pumping but their cheap to me.

I would like to ad more thoughts; Mount the manifold high if you can and install a hose bib for a 4th outlet there.
The higher the manifold helps ensure the 3 ACs get a lil more even flow instead of the top one possibly getting less.
There is some name for this that escapes me at the moment, I did find this picture;

Or, install all three hoses up to the same height, then town to their own condensing station.
Just imagine the same weight of water to each unit.

The hose bib makes a great bleed and test valve and a good connect for back flushing.

Oh Yea, I luv spending O P M.

Good advice. I also like having shut down valves on each so I can backflush or descale each unit separately if needed

Flagship is great. I got my chillers and air handlers from them 5 years ago. Very helpful to answer any questions during installation. I ve also gotten 5 replacement air handlers for the 110 in the last couple of years.