Total BTU/H Capacity of All Self Contained Units to be Supplied by a Single Seawater Pump

Systems With More Than One
Self Contained Unit
Using a Single Seawater Pump
A boat that requires more than one self contained unit to properly cool the boat faces a new question: Do I use a separate seawater pump with each self contained unit or Do I get a single pump with enough capacity to handle all of the self contained units on the boat?

If you decide to purchase a single pump with enough capacity for all of the self contained units on your boat use the following guideline.

Recommended Minimum Pump Capacity in
Gallons Per Hour (GPH)


Seawater Pump **

**When a pump will be operated on 50 Hz power, use the next larger size pump
The practical limitation on the number of self contained units that can be supplied from a single seawater pump is six. The reason for this is that a pump relay must be used to interface between the self contained units and the seawater pump. The pump relay will turn on the seawater pump whenever any of the self contained units are turned on in a multiple self contained unit system. The standard pump relay, the AQP6R, will handle up to six self contained units on a single seawater pump and can be used on all pumps up to an AQPM-15. If the AQPM-30 is used, use the AQP6RC pump relay.

To see an example of how multiple self contained units are electrically connected to the pump relay and seawater pump, click here.
For systems with multiple self contained units supplied by one seawater pump please consult with the sales department at Aqua-Air about the piping. This is a very critical part of the installation. If done incorrectly the self contained units may not receive enough seawater flow to operate properly.