Waterfall feature and WF-28/011774 pump/motor downsizing

[CavVet]

Getting to know my pool a bit more, i decided to tackle another small issue.
when we are running our waterfall feature, the pump/motor is very loud. Up until recently, we just accepted it.
I decided to examine the plumbing a bit more, and found a valve that was more than half way in the closed position.

When i opened it further, the waterfall (and subsequent tanning area jets) became the Colorado river rapids and the tanning area jets shot up easily 10' high.
i shut it down again and realized the 'noise' is the pump/motor/water in restriction.

my question: is there any reason why i couldn't go down to a smaller motor? say a 1hp motor so i can open that valve all the way, thereby eliminating the restriction? as long as it is a 56Y frame, any 1hp motor should work correct?
Thoughts?

 

[jblizzle]

I think you might be misunderstanding the valve. The picture shows that the left pipe is partially closed and the right pipe (with the the 2 other valves) is completely open. Those 2 valves on the right are completely open.

The valve is not adding any total restriction as the water that does not go left will just go to the right.

If you want to go to a smaller motor, you also need to go to a smaller impeller. If you went to a smaller motor on the existing impeller, the motor will be overloaded and quickly fail.

 

[CavVet]

I see. So, in practice, if i were to fully shut that upper valve, i'd be bypassing the two lower right valves and going down that single line.
the two valves to the right control the flow to the waterfall and secondly to the tanning pads. i do not recall where that bypass line goes to.
perhaps tonight it is time to investigate further.

I think i'll try fully opening that single valve and partly close the two on the right to see if that noise remains.

 

[jblizzle]

Do you see on the handle where is says "OFF" that is what is closed. If you "fully closed" it (off facing up in the picture) you would dead head the pump and no water would flow.

Unless you mean fully close the left pipe which would force all water to the 2 pipes on the right.

 

[RedBluePool]

That Whisper flow pump will get loud if it doesn't have enough back pressure of 11 psi.

So you might have to use the valves to restrict flow to quiet the pump down. That means a smaller motor will have the same issue.

Try closing off the 2 valves to the right a bit and see if that quiets the pump down.

 

[CavVet]

Got it figured out!
On the supply side(picture above), the left pipe feeds the waterfall, the two pipes on the right (with valves) go to the two tanning areas.
I opened the main valve up top and did as you both suggested and (slightly) closed the tanning area valves...doing so made it TONS quieter, and there seems to be equal water flow to all areas.

I appreciate all the guidance!

 

[jblizzle]

Great!

Just a note that the valves are on the "return" side of the pump ... before the pump is usually called the "suction" side. That is the typical terminology.
"supply" side can be confusing ... am I supplying the pump or supplying the pool ? ... although I suppose you could say the same about "return"