Best New Pool Motor Recommendations

[my12by60]

Our pool was built in the summer of 2000. The first two-speed motor lasted until September 2008. The existing two-speed motor, which is still running ok, was installed at that time. So the existing motor is 8 years old. I decided to try something new and wise, which is to do my new motor research in advance instead of after my current motor fails. Here are the specs for our pool:

location: Phoenix area
15,900 gallons
2" return lines, 2.5" suction lines (both about 50 foot runs)
in-floor cleaning system (MagnaSweep by A & A Manufacturing, 6 zones, 27 heads)
in-deck chlorinator
no water features and no spa
WhisperFlo pump WFE-28
Purex cartridge filter system (405 sq. ft.)
A.O. Smith 2-speed motor, 2 hp high, .33 hp low (not sure of low speed hp as label is no longer readable)
Cost for power: about 11 cents per kw

My wife insists that the pump be run 24/7 during our warm season (May-Oct) as she takes care of the chemicals and she loves a spotless pool. We are set for 22 hours on low and 2 hours on high. So factor that non-negotiable issue into any motor recommendations. I might be able to sell her on reducing the high run time to one hour. The original electrician wired in two Intermatic mechanical timers in a side-by-side configuration that allows us to use the timers to automate the the low speed and high speed run times of the two-speed motor.

Since the pump body seems to be doing its job, I hope we can just go with a new motor only, unless there is some compelling reason to upgrade both pump body and motor that I am not aware of.

Given all of these parameters, does anybody have any thoughts on what would be good options as a replacement motor once our existing motor dies?

Should we go two-speed again or would we see benefit in a VS?

 

[RobbieH]

The advantage to VS is that you can go really slow during your low time. Mine's on around 1600-1650 RPM, which is about 27 GPM, and pulling around 325 watts. You will probably be more efficient and can go FAR lower than that since you only have a 15,000 gallon pool. But, whether it's worth it to you or not depends on the cost of your electricity.

Are you using that chlorinator with tablets? That is probably a bigger issue.

11 cents a kWh is just a penny more than I pay, so we have cheap power. Probably not worth the extra expense, I think the VS is about $850 right now IIRC.

 

[my12by60]

If my understanding of the specs on my current motor are correct, then the low speed is .33 hp and 1725 rpm. I don't know how that translates into watts. Another thing I don't know is how low we can go on RPMs with the in-floor cleaning system. Will the heads even pop up and move any water and dirt around at very low RPMs? I am sure you don't have in-floor in your 1957 pool, but maybe somebody else with in-floor will chime in.

The 3" inch tablets in the in-deck have not been a big problem for us. We do a full drain and refill every three years due to fill water that is hard to start with plus heavy water turnover due to evaporation as a result of our hot climate. I know many people would hate to deal with that, but I have a good submersible pump that makes the job easy. The refill cost on the water bill is less than $100. So the convenience of using the tabs is worth it to us in exchange for dealing with the 3-year drain/refill cycle.

 

[RobbieH]

There are some basic ways to translate that into watts, MAS95 is really good at it, but there are other factors such as the head losses and such that I am not good at calculating. I have to push my water through a 1.5" return, which makes the pump have to work harder than yours will for the same GPM most likely, for example.

Gotcha on the drain/refill. For some, it's an option. I can't imagine having to drain my pool and refill.

 

[bobodaclown]

What's your electric cost KWH? Sounds like your motor/pump combo is working fine. When the motor goes just replace it with compatible one, or replace the bearing yourself. Motors normally die from bearing failure. Bearings lose lubrication, or get wet due to a bad seal on the pump shaft, start to make noise and drag, the added drag, in turn causes the winding to heat up, winding get hot enough to burn through/melt the insulation, then short out. Phoof.. New motor needed.

Personally, if it isn't broken, don't fix it.

My 2-speed motor bearing were making noise, bought replacement bearings, in an hour I was back up and running. Lots of info on youtube, you can find bearing cheap on eBay.

 

[RobbieH]

He said 11 cents.

 

[my12by60]

Cost per KWH is about 11 cents. So I am still not sure whether we could achieve much savings with an entirely new motor that runs at lower rpms on low speed or even if running at lower rpms would be desirable from a circulation and cleaning standpoint.

I like the idea of doing a preemptive bearing replacement if the current motor starts to sound bad. Did you replace your shaft seal also at the same time? What other replacement parts would I need to have on hand if I went this route instead of getting an entirely new motor?

 

[RobbieH]

At the speed I have mine running at, for my very large pool, I estimate $33 per month. It will be hard to get much lower than that. But, with your size pool, you can probably cut the run time in half and still be spotless.

 

[bobodaclown]

At $.11 KWH the price difference in a VS and 2-speed you won't recoup the difference in cost in price savings.

 

[sargent]

I see three options, assuming 24 hour per day pumping.
1) Replace motor with a two-speed. Initial cost will be about $300, including seal kit. Electricity cost will be around $45 per month.
2) Replace motor with a variable speed. Im thinking of the Ecotech EZ 3 hp. Initial cost will be about $475, including seal kit. Electricity cost is likely to be around $30 per month (assuming low speed is set at 1000 rpm).
3) Replace pump with a variable speed pump. Initial cost will be about $930. Electricity cost is likely to be around $23 per month.

Option 1 is initially the most cost-effective. After about 12 months of operation, option 2 becomes the most cost-effective. Option 3 never becomes the most cost-effective. At six months of operation per year, that means the variable speed motor would have a payback within two calendar years.

It would be really good to cut down on the hours of pumping per day. Surely your wife is not up all night long. How about run on high for two hours early in the morning to clean the floor, and then switch to low for the rest of the daylight hours to keep the surface skimmed? So, maybe two hours on high and ten hours on low? With that run time, option 1 electricity cost is about $28 per month, and option 2 becomes about $22 per month. At that rate it would take around 4 calendar years for the variable speed motor to be most economical.

 

[my12by60]

Sargent,

Thanks for the analysis of options. Looks like the Ecotech EZ 3 hp could be a good way for us to go since we get to keep our existing pump and save almost $500 in up-front expense. The power savings by going to an entirely new pump and motor (your option 3) are not large enough to recoup the extra upfront cost in any reasonable amount of time. By the way, we will still be running the pump for the other six months of the year, just on reduced hours vs. my wife's 24/7 preference for the hot months.

You mentioned running a variable speed motor on low at 1000 rpm. Will those low rpms work with our in-floor system?

What rpms would you recommend for the 2-hours of high speed operation?

Also, what is the reputation of the Ecotech motor for longevity?

I also see you recommend at 3hp motor vs. our existing 2ph motor. What is the reason to upsize the hp when going to a variable speed motor vs. a 2-speed motor?

 

[joeld]

My Paramont cleaning system manual says the pumps must be capable of maintaining 20 psi on the water valve (six port as I recall) , mine runs about 18 psi and all the pop ups work. I have however cleaned around all of them as they do collect small particles.

 

[Poolray]

We got the V-Green 165 motor on sale for a little over $300. In addition to the power savings, it is very quiet at low speeds. At 1350 RPM it sounds like crickets or a refrigerator running. This is great for us since the patio is pretty close to the pad. You would have to experiment with different pump speeds to power the equipment you have, and for how long. This motor is programmable with 3 steps that cover 24 hours, plus an override. In each step you set the run time and motor speed.