How to determine low speed flow of 2 speed pump?

[jgresham75]

Looking at Pentair Dynamo 2 speed 3/4 hp pump. They give flow chart for high speed but no low. How can I determine if this pump can handle my pool on low speed without the flow dynamics of the pump at low speed? (I have already calculated total head and flow needs of my setup)

Head 25
100 sqft cartridge-flow30-35
15000 gallons 15x30

Thanks

 

[jgresham75]

Actually found another thread saying that flow is cut in half on low speed. Guess this answers my question.

 

[Rangeball]

That's my understanding.

I belive head loss is too.

Fyi, I recently emailed Pentair for the flow chart on the 2 speed dynamo, they told me they don't have it for 2 speed, only one speed.

 

[mas985]

From pump affinity laws:

GPM Low Speed = GPM High Speed / 2
Head Loss Low Speed = Head Loss High Speed / 4