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Re: A/C raw water pump

Posted: April 3rd, 2021, 8:46 pm
by Viper
Did you confirm whether they're ignition protected?

Re: A/C raw water pump

Posted: April 3rd, 2021, 9:53 pm
by tonyiiiafl
Their site says it is and same pump used by domestic. However the windings are exposed and it is a brushless design. Pretty much like the March but that says right out it is. Pretty confusing.

Re: A/C raw water pump

Posted: April 15th, 2021, 8:23 am
by Dad Joke
Here's the formula:

For an open system, 2gpminute/ton (1 ton=12,000btu)

Re: A/C raw water pump

Posted: April 15th, 2021, 9:01 am
by Midnightsun
Dad Joke wrote:QR_BBPOST Here's the formula:

For an open system, 2gpminute/ton (1 ton=12,000btu)
That formula cannot apply to boat systems. Larger systems found on our size boats usually are around 36,000btu like mine. That would be 6GPM convert to GPH X60 = 360GPH. They do not even make pumps that small. Standard pickings are 500,750 and 1000gph for our boats.

Re: A/C raw water pump

Posted: April 15th, 2021, 5:21 pm
by tonyiiiafl
I could not confirm the KoolAir was ignition protected. I did confirm the March is. I did buy the same one that was in there as I can just pipe up with no changes. March is a quality pump compared to the KoolAir.

Re: A/C raw water pump

Posted: April 15th, 2021, 8:09 pm
by bud37
Good idea on your part Tony.... The idea to remember is that the flow rates in the air unit specs are what the unit wants to see not the advertised flow rates of the pumps......to get a better idea of your actual flow rate it would be measured at the discharge thru hull.

Re: A/C raw water pump

Posted: June 28th, 2021, 6:47 pm
by PM16127
I just replaced my main pump in my 1988 Mariner 28. I ordered it from Burt Process. Their prices were very reasonable, and I had it within a week.

Re: A/C raw water pump

Posted: June 28th, 2021, 7:00 pm
by tomschauer
The pump flow rates are listed as maximum, with no head. Your piping and heat exchangers provide significant head loss. You need to look at the pump curve and either figure your head loss by doing the math on the tubing / fittings and heat exchanger(s) or look at the curve for the pump you are replacing (much easier) to be sure you have the capacity needed.