Normal PSI at low rpm?

[NaCLTPool]

Is this PSI on my filter normal if running at low rpm (800)? I can feel water coming out of the returns

 

[NaCLTPool]

 

[Jimrahbe]

Na,

Yes, you have a 60 lb. gauge. I have a 30 lb. gauge and I get about 1 or 2 lbs. at 1200 rpm..

Kind of the whole point of big pumps running slow...

In general, you don't get any savings below about 1000 rpm..

Thanks,

Jim R.

 

[Jimrahbe]

Na,

Are your skimmers working at 800 rpm? How about your salt cell? If not, what is the point???

Thanks,

Jim R.

 

[NaCLTPool]

Na,

Are your skimmers working at 800 rpm? How about your salt cell? If not, what is the point???

Thanks,

Jim R.

I run it for an hour at 2500rpm in the morning and 2500rpm for an hour in the evening. This time of year I have no debris and also have a skimmer robot. Salt cell is off because of water temp but it functions at 800rpm.

 

[NaCLTPool]

I run it for an hour at 2500rpm in the morning and 2500rpm for an hour in the evening. This time of year I have no debris and also have a skimmer robot. Salt cell is off because of water temp but it functions at 800rpm.

To add to this, I just checked it running at 2500rpm and it was at 10 psi

 

[uraceulose]

Mine is at 0 psi at 750 RPM.

2500 rpm is 10-11 psi on mine as well.

 

[NaCLTPool]

Mine is at 0 psi at 750 RPM.

2500 rpm is 10-11 psi on mine as well.

Good to know. Sounds like everything is working as intended

 

[JamesW]

I just checked it running at 2500rpm and it was at 10 psi

This should be approximately correct.

The gauge starts at about 2 psi, which is about 4.62 feet and the gauge is probably about 4.62 feet above the pool water, so it actually takes about 6 psi to make the needle get to the first line (4 psi).

If you start slow and increase the speed in increments, I suspect that the needle will begin to move at about 1,200 ppm.

1,200 ppm is probably a good low speed for you with good flow at low power.


Speed.........Flow (GPM).........Power (Watts)......Pressure (PSI)

800.....................28...........................30............................1

1200.................42...........................100............................2.3

1600.................56...........................236............................4

1725.................60...........................300............................5

2500.................87...........................900.........................10

3450.................120......................2370..........................19

Fan Affinity Laws

The affinity laws can be used to calculate resulting volume capacity, head or power consumption when speed or wheel diameters are changed.

www.engineeringtoolbox.com

 

[JamesW]

TFP is a registered 501(c)3 non-profit that is maintained by user donations.

The people who answer questions are volunteers.

If you find the site to be a good resource, please consider making a donation to help support the site.

Thanks.

Become a TFP Supporter

Help Support TFP Trouble Free Pool is run by a dedicated group of volunteers that … Read more…

www.troublefreepool.com

 

[flynwill]

I have the identical gauge on my filter and it reads zero at 1400 RPM. I also have a flow meter and can say that this is at ~45 GPM.
As Jim said this is the whole point of running big pumps at low speed, much less energy lost to friction.

To gauge whether the filter needs cleaning check the pressure during the pumps prime cycle.