Low speed enough to run SWG?

[dan4jc]

I'm looking at replacing my current 1 speed pump with this 2 speed: A.O. Smith 1 H.P Square Flange Dual Speed Up Rate Motor - UQS1102R - INYOPools.com


My concern is having enough power at the low speed setting (1/6 hp) to run my SWG. The requirement is a minimum of 20 GPM. My equipment pad is less that five feet above the height of the water. Is there an easy way to figure out whether this pump would be sufficient?

 

[JVTrain]

This would depend on the amount of head (or resistance) in your current plumbing configuration. If you look at this performance curve, your motor would be the B and G curves, assuming that the Pentair 1 HP, 230V, 2-speed Whisperflo that uses this same motor is equivalent.

I'm not sure of a good way to determine your feet of head directly... but as long as you had less than ~20 feet of head in the system, it would be over 20 gpm at low speed, unless I am mistaken.

 

[mas985]

It should not be an issue unless you have a lot of head loss in the plumbing. What was the clean filter pressure?

 

[dan4jc]

I'm not sure of a good way to determine your feet of head directly... but as long as you had less than ~20 feet of head in the system, it would be over 20 gpm at low speed, unless I am mistaken.

JVTrain, I have tried to read/understand the process of determining feet of head, but am still confused. How is this determined?

It should not be an issue unless you have a lot of head loss in the plumbing. What was the clean filter pressure?

mas985, my normal clean pressure is around 11 psi.

 

[mas985]

It doesn't seem like your plumbing is overly restrictive so it shouldn't be a problem.

As for determining head loss, there are a couple different methods I use and I have a couple tools in my signature that helps with that but I don't think you need to go to the trouble. 20 GPM on the above head curves is very restrictive and I don't think I have seen a pool yet with that restrictive of plumbing.