T&T: AC raw water pump flow rate?

[Steve Sipe]

Keith wrote:
> Well, my AC raw water pump went out. It's a March AC-5C-MD, rated at 16.5 
> GPM. The water flow has always been adequate, barely. I was wondering if I 
> could upgrade to their 5.5 series, which is a 30 GPM flowrate, without 
> blowing my water circuit all to hell?
>   
What's the total btu? That's what determines the GPH flow requirement. 
The 30 GPM will do 9 tons. You don't have a 4 & a 5 ton unit, do you?? 
<G> Bigger is not necessarily better. Size the pump to do the job it 
needs to do. Would you take out your 135 HP diesel propulsion engine & 
replace it with an 800HP?

Your 16.5 GPM will handle up to 5 tons. Allow 200 GPH/ton (12,000 btu). 
Make sure the circuits are piped so that they're proportional for the 
btu requirements of the condenser.

Steve