2 speed motor for hayward powerflo matrix?

[singingpond]

I just purchased a pump/sand filter combo unit on Amazon, because of the unusually low price:
Amazon.com : Hayward Pro Series S210T93S 21-Inch Top-Mount Above Ground Pool Sand Filter System with 1.5-HP Matrix Pump : Swimming Pool Sand Filters : Patio, Lawn Garden
[I'll note for future reference that the price for this unit, today, is down to $147; it was a few dollars higher when I bought it]

This appears to be a good price for the 21" sand filter, which is what I was mainly after with the purchase; however, the packaged 1.5 hp single speed pump seems oversized for what we'd like in the long run. We'll probably run the unit as is, for a few days, when it arrives next week (just to check if everything works OK out of the box), and then swap in a 2-speed pump in the spring.

One option would be a motor replacement. If anyone would be willing to double check that this motor (below) is appropriate, that would be a big help!

Looking here for replacement parts for Hayward Powerflo Matrix pumps:
Hayward Power-Flo Matrix Replacement Parts

And then option 15d from the above page, a 1 hp 2-speed motor:
Motor 1 to 1/8 HP 2 Speed Threaded 3450/1725 RPM 115 Volts 60Hz 11.0/2.9 Amps SF 1.0 48Y Frame

Does that look right? Is that an off-brand motor at that price?

Is there a recommended website where people buy replacement pump motors?

My other pump option, which I had more or less decided on before jumping on the unexpected Amazon deal, was a Pentair Optiflo
Amazon.com : Pentair 347990 OptiFlo Vertical Discharge Aboveground Pool Pump with 2 Speed Motor and Standard Plug, 1 HP : Swimming Pool Water Pumps : Patio, Lawn Garden

Advice or comments would be greatly appreciated!

 

[banditig]

That was a good price. Yes oversized but might as well use it. If you have a place to store the Matrix to keep as a back-up then other is good choice.

 

[Unior]

The worst thing that could happen with an oversized pump is risk of entrapment at the suction port or wasting electricity. You could run the pump on a timer and make sure theres a good screen/skimmer/prefilter on the suction tube to reduce risk of entrapment. Heck, I run a 2500gph filter on my kids 1000 gallon pool. I only run the pump a few hours a day on average or whilst slamming though.

 

[mas985]

That pump is not really over sized. It produces about the same flow rate as my 1/2 HP IG pump. AG pumps are of rated much higher in HP than they actually produce in terms of flow rate. Sizing or judging a pump buy just the HP rating is likely to lead to the wrong conclusion.

 

[singingpond]

OK, thanks, I will consider an upgrade to a 2-speed pump to be somewhat less urgent! However, for using less energy, wouldn't that still be a sensible path (running on low speed most of the time)?

I actually wasn't going just by the hp rating; I was comparing the Pentair Optiflo 1 hp (the pump I was originally planning to buy) to the Hayward Powerflo Matrix 1.5 hp, in the pump flow rate graph in your Hydraulics 101 article. The Hayward pump doesn't look all that different on that graph; however, since the one I'm buying isn't the dual speed model, I wouldn't have the option of turning it down for lower flow rate and electrical usage.

 

[mas985]

Yes, low speed will save about 75-80% in energy. However, in many cases, you can just shorten the run time for a single speed and save some money as well.

 

[singingpond]

Thanks for the additional comments!

Tracking shows that the pump + filter will arrive here Thursday -- I'd better scramble to scrounge up some filter sand to give it a test run. That was quicker shipping than I expected!

If anyone has comments on my original question (whether the replacement dual-speed motor I linked in the original post would fit), I am still curious about that.

 

[mas985]

And then option 15d from the above page, a 1 hp 2-speed motor:
Motor 1 to 1/8 HP 2 Speed Threaded 3450/1725 RPM 115 Volts 60Hz 11.0/2.9 Amps SF 1.0 48Y Frame

You would need 15e not 15d.

 

[singingpond]

Thanks - I wondered if the 1 hp motor would fit in the same enclosure, with the same impeller; hence the question about 15d. From what you say, I would have to stick with the 1.5 hp dual-speed motor. Good to know - I had assumed that a number of motors might have the same physical size, even with different hp ratings.

 

[mas985]

The motors are identical size. That isn't the issue.

A motor needs to be sized for the installed impeller. If you install a 1 HP motor with a 1.5 HP impeller, the motor will overheat and shut down. You could replace both the motor AND impeller with a 1 HP if you also want to downsize.

11b (double check this) with 15d.

It looks like Hayward used the same impeller for three different motors:

SPX1500L - Hayward - IMPELLER, SP1500-L, HAYWARD 1, 1 1/2 & 2 HP

If true, then the impeller you have might be ok with a smaller motor. However, it really wouldn't make any difference because the impeller determines the load and the current draw from the motor so either motor would have similar energy use.

 

[singingpond]

Thanks for taking the time to explain these interactions between pump components. Very helpful!