VS Pump Minimum Flow

Jun 11, 2011
10
Phoenix, AZ
I have a 32500 galloon pool with Pentair VS Pump. Pump is below grade and a long run to the pool (about 50 feet). When I set it at a very low RPM <1800, I feel no appreciable movement of water from the 6 different outlets but I do see water movement in the filter basket (barely) and movement of water in the pot at the pump. So I know water IS moving but with MINIMAL perceptible flow at the outlets. I do NOT have a flow meter but wondering out loud how much flow I really do have? Is there a minimum pressure and flow that is needed to overcome head pressure?
 

duraleigh

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You report a 32.5 K pool in your post but only a 23k pool in your sig. Correct whichever one you need to. Pump at 1800, what is the psi?
 

Jimrahbe

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NL,

In my mind, the slowest speed you ever want to run is the speed that turns on your SWCG, plus 100 RPM.. For me this is 1200 RPM, but I don't have a heater.. Since you have a heater, then your 1800 sounds about right to me.

You don't need to see much "action" in the skimmers for them to work well.. Do you have a working weir doors?

Thanks,

Jim R.
 

mas985

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May 3, 2007
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I have a 32500 galloon pool with Pentair VS Pump. Pump is below grade and a long run to the pool (about 50 feet). When I set it at a very low RPM <1800, I feel no appreciable movement of water from the 6 different outlets but I do see water movement in the filter basket (barely) and movement of water in the pot at the pump. So I know water IS moving but with MINIMAL perceptible flow at the outlets. I do NOT have a flow meter but wondering out loud how much flow I really do have? Is there a minimum pressure and flow that is needed to overcome head pressure?
Yes, for every RPM value there is a maximum head where the flow rate stops. What is the filter pressure at full speed?
 
Jun 11, 2011
10
Phoenix, AZ
NL,

In my mind, the slowest speed you ever want to run is the speed that turns on your SWCG, plus 100 RPM.. For me this is 1200 RPM, but I don't have a heater.. Since you have a heater, then your 1800 sounds about right to me.

You don't need to see much "action" in the skimmers for them to work well.. Do you have a working weir doors?

Thanks,

Jim R.


Corrected my "signature". The salt cell is dead and is inactive. Back to use chlorine. But its still inline. And the heater. Well I live in AZ and the pool is 90 degree from June-Sept without any heat applied.

The weir doors are working fine. But If I hold it "closed". The suction isn't even remotely strong enough to draw down the level in the basket area. Unless at full speed.
 
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mas985

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Those values are dead head and there is no wonder you are not getting any flow rate, if correct. Does the filter gauge go to zero when the pump is shut off? Can you post some pictures of your plumbing setup?
 

Jimrahbe

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The suction isn't even remotely strong enough to draw down the level in the basket area. Even at full speed.

NL,

With the skimmer door held up the skimmer basket should empty in a few seconds...

Based upon Marks comments, your water has no place to go..

Show us some pics of your equipment pad..

Thanks,

Jim R,
 

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Jun 11, 2011
10
Phoenix, AZ
Those values are dead head and there is no wonder you are not getting any flow rate, if correct. Does the filter gauge go to zero when the pump is shut off? Can you post some pictures of your plumbing setup?


So at rest. The pressure reads about 3 Psi.

I can confirm at RPM of 3100 that the skimmer basket is drawing water steady and the weir door is full open.

IMG_3886.jpegIMG_3887.jpeg
 

mas985

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Is the filter guage below pool water level? If so, by how much? If not, you have broken gauge.
 

mas985

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Is that why the equipment is elevated off the ground?

If the guage is correct, you have a serious plumbing problem.
 

mas985

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Because the head loss in the plumbing is way too high. The pressure readings you have should be half what you are seeing.
 

JamesW

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Mar 2, 2011
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When is the last time that you took the filter apart and cleaned it?

Check the cell for scaling and debris.
 

duraleigh

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You are in VERY good hands with Mark and James W. That psi is telltale and surely indicates a problem but they are the right guys for the job.
 
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