Flow rate advice: Will a 2-speed Superpump produce adequate flow on low speed for SWG

Swampwoman

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Apr 27, 2012
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Grand Rapids, MI
#1
Hi all. I'm looking for in-the-field experience as to whether the "low" flow on a 2-speed Hayward Superpump is too low for SWG production or heater operation.

My Hayward Superpump 1 HP single speed needs a new seal, and if I hire the labor out...am thinking I might as well upgrade to 2 speed...I will go dig up the specs and try to predict, but if you've run this pump and have any observations, please share.

The hayward specs don't seem to show rpm on low.

Oops, Hayward's site des say 1725 rpm

I think my question now is whether on low speed it would produce adequate flow for the heater...
 

woodyp

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Apr 17, 2010
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East Texas
#2
I think the minimum for a SWG is only like 15 gallons per minute flow for it to produce. The heater may be a different story.
 

Swampwoman

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Apr 27, 2012
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Grand Rapids, MI
#6
Like magic...I say his name and he arrives ;)

My pipe is 1.5"

My SWG is Aquarite t15.

My heater is Raypak 266 with a min of 25 gpm I think.

My plumbing is close, eg about 20' ish from poolhouse to edge of pool...skimmer and 1st return opposite of it are on this end.

I have 2 more returns at the other end of the 30.5' grecian pool (18.5' wide)

There is approximately a 8-10" rise from pool area to concrete floor of pool house.

Flow never metered but has seemed robust with the 1 hp hayward - Maxflo, btw, I was wrong when I said superpump ;)

Gotta get back to work but will check in later ;)
 

mas985

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May 3, 2007
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Pleasanton, CA
#8
Like magic...I say his name and he arrives ;)
I can't resist a thread with "flow rate" in the title.


My SWG is Aquarite t15.

My heater is Raypak 266 with a min of 25 gpm I think.
The Aquarite has a minimum flow rate of around 11 GPM so the heater is likely to be the limiting factor. Although heaters usually work on pressure not flow rate so you sometimes can adjust the pressure switch a bit to get them to work on low speed.


low never metered but has seemed robust with the 1 hp hayward - Maxflo, btw, I was wrong when I said superpump
MaxFlo is about the same ~25 GPM.
 

Swampwoman

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Apr 27, 2012
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Grand Rapids, MI
#9
Thanks!

I'm pretty tempted to go with just upgrading the existing motor to the 2-speed equivalent because even if on the worst winter day I'm running the heater 10 or 11 hours worst-case at full speed to satisfy both the heater and fact that im also running flow through the air warmer exchanger...I could still schedule low speed the rest of the day.

I've run a bunch of the calculators now around the web. I don't seem to ACTUALLY be using the energy the calculators say I should with my single speed. Eg. The differential of a December without pool operation at all versus this December with 24/7 operation PLUS the air blower running constantly (eg in 30 second cycles 24/7) isn't as wide as it should be.

I wonder if just actually running the pump nonstop without startup makes my kwh usage dramatically lower. Ive not yet found any other explanation and have no way to isolate usage.

I do know that motors draw more on startup...first hand generator experience drove that one home ;)

In which case, would a motor switching speeds cause a "startup" style draw?
 

mas985

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May 3, 2007
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#10
The startup current is insignificant compared to operational current.

But I have an issue with you using energy calculators from "other" sites when you have a world class version here on TFP. ;-)
 

Swampwoman

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Apr 27, 2012
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Grand Rapids, MI
#11
^We have a pump energy calculator? Or do you mean YOU? ;)

So for a 1 hp pump, the places I saw calcs are using 1.73 kwh x run time. ( My max amp at 230 v is 7.5) I've been running 24/7 at .15 (15 cents) per kwh, which would be 41 kwh per day. My electric bill "should be" about $185/mo different operating 24/7 this winter vs 0 last year. but its not, even at the highest differential.

I did come across a post last night on a pool site where someone pointed out that considering service factor was necessary, and that efficiency made a difference and that 1 hp typically uses about 730 kw.

When I calculate at 730 instead of 1725 I get a number that could reasonably be more like my differential...but if true, the 115v/7.5 amp air blower that maintains the dome is also using less energy than we expected.

So, IF this means I'm pumping 24/7 for less than $80/mo...then my site must have decent or at least not impeded flow...eg filter is large enough, not a lot of bends and ergo pump uses less energy...but I do have heater and chlorinator.

Swamp hubby has pointed out that it would suck to upgrade the pump to 2 speed or variable when its still working great and for any reason find we were already using as little electric as possible for winter operation ;) If I could truly operate for 50% less it might be worth the preemptive swap. Otherwise, maybe I should just swap out the seals and wait until my hand is forced ;)

Is there any way I can use my multimeter safely to tell what the pump is drawing?
 

mas985

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May 3, 2007
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Pleasanton, CA
#12
In my signature there is a spreadsheet that allows you determine not only flow rates but energy usage. But the MaxFlo 1 HP uses around 1100 watts and on low speed, around 260 watts.

Is there any way I can use my multimeter safely to tell what the pump is drawing?
Does the house power meter have a digital readout? Just compare the wattage with the pump on vs off.
 

Swampwoman

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Apr 27, 2012
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Grand Rapids, MI
#14
@pooldv

Re
Hey, what about a 1.65hp variable speed Maxflo? Then you can dial it right in.
I think you're right on the money on that one....INYO says I can upgrade to that motor without even changing the impeller, just need the seal kit...AND the pool service guys figure the labour is almost the same as the seal job.

So for $400 (motor) plus labour I can dial it precisely to whatever the Raypak needs, step it WAY down whenever the Raypak is off, (in the winter i only run my swg for 1.5 hrs at a low %) and not have to worry so much about how-to-calculate-head...and get my money back in a year of service.

And the bonus would be have a working backup motor on hand in case of catastrophic winter failure...no waiting for parts or service in a critical below freezing situation. The numbers make sense.

So thanks, guys, as usual for helping me noodle through this! I think I have a decision path!
 

Swampwoman

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Apr 27, 2012
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Grand Rapids, MI
#16
Here's the link to the motor:
A.O. Smith 1.65 HP Variable Speed Pool Pump Motor Round Flange - ECM16CU - INYOPools.com

They call it the ECM16CU and its $399. It is Century, which was former AO Smith as I understand it...my pump motor was the AO Smith uprated 1 hp model C48K2N143B1...I had them check against the model number - round flange ;) Apparently they also make a square flange version too, so other pumps can be retrofit with this variable speed unit too.

In my case, I wanted something that fit existing housing in case I needed o swap back in emergency.

Ps - mine just says Max Flo.
 

Swampwoman

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Apr 27, 2012
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Grand Rapids, MI
#20
Gotcha. I like the notion of having the wet-end swapable with a working backup given the winter operation concerns.

This winter when the Raypak board fried during automation rewiring, I had to wait a few days for the local guy to get the new board that ultimately was needed. The heat held well enough that it wasn't a problem, but I realized then that if the pump ever went I'd have a serious problem, especially with the few feet of exposed PVC that runs from the pool house across the sidewalk before going underground. We've sheltered it with an insulated box and have a temp monitor and alarm inside, and I do have a pipe warmer avail for the box as a backup, but I'd kinda determined then and there that having a backup pump was a near future goal ;)

Sometime I wonder though if these precautions of mine have a causation role - eg drawing misadventure to myself ;) About a month after I similarly twigged to the fact I would be in trouble in the event of a multi day power outage, and bought the Generac and had the interkit installed, we had our first multi day power outage here. We hadn't had one in the 6 years we've owned the property.

Swamp-hubby said I must use my powers of disaster forecasting for good ;) (I think I DID use them for good...bought the generator, right? Not MY fault we had to use it ;) )