Installing new AC System 2 Questions

Greatlaker221 said:

The units are above the water line under the salon satee. The strainer and pumps will be below the water line near the 2" seacock The pumps and ac units are all 3/4" so I need a manifold going from 2" to 2/4.

I found a Vetus manifold that is one inch supply to three 3/4 outlets, I wonder how 1" can supply 3 3/4 outlets if all are needed at same time?

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No, the manifold is after the pump. So you either mount it directly on the outlet of the pump or down stream of the pump. So it does not need to be 2" inlet to two 3/4" outlets.

To feed two 24,000 btu units I think you'll find you need a pump this size: March Magnetic Drive Pump

Capt.Bill11 said:

You could just wire the pump old school to a breaker and use the breaker like a switch. Turn the pump on when you are using both or either unit. And turn the breaker off when your not running the units.

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I remember hearing that ABYC standards specifically state a breaker should not be used as an on/off switch.

https://www.bluesea.com/products/category/14/33/Circuit_Breakers/C-Series

Circuit Breakers - C-Series

Magnetic hydraulic circuit breakers that combine switching and circuit protection into a single device.

Funny they would advertise the switching ability....

No Mast said:

I remember hearing that ABYC standards specifically state a breaker should not be used as an on/off switch.

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Apparently a lot of boat manufacturers are unaware of that fact. Or perhaps like me they don't care.

Most of this has been covered by others, but here's what's on our boat. One pump with it's own breaker that supplies water to three AC units. When the pump is on there is water flowing through all three units. Each AC unit has it's own breaker and wall switch with thermostat. Each unit has it's own above waterline thru hull without a seacock. I don't know if there are anti-siphon loops installed. There are also condensation drains that go to my two shower sumps. We have a 50 amp shore power inlet, so the AC will not run when we are hooked up to 30 amp. In that case we have to run the generator. Luckily, we live in the Pacific Northwest and don't need AC that often.

porman....I have a 50 amp service with a 30 amp adapter that feeds both main AC busses so I can run all 3 of my ACs if I chose.


Wonder why your setup is different? Unless your AC is 220V.

psneeld said:

porman....I have a 50 amp service with a 30 amp adapter that feeds both main AC busses so I can run all 3 of my ACs if I chose.


Wonder why your setup is different? Unless your AC is 220V.

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Yes, it is. I forgot to mention that.