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Thread: Homemade Variable Speed Pump

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    bobodaclown's Avatar
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    Homemade Variable Speed Pump

    OK here's my question.
    I purchase a Variable Speed controller such as: SMV AC Vector Drive - ESV751N02YXB
    It cost about $200. ESV751N01SXB ESV751N01SXB 751N0: 1 HP (.75 kW) 1SX: 120-240 Volt, Single Phase $218.90
    http://www.wolfautomation.com/produc...ech-smvector-b
    http://www.wolfautomation.com/assets/15/smvector.pdf


    Pick up a 3 phase motor: 1HP 3 phase square mount another $200
    http://www.grainger.com/Grainger/AO-...Y44?Pid=search

    So for $400....
    Mount it to a 1HP Intelli flow body or use as a replacement for a 1 HP. Then you have a Variable Speed Pump

    Also see this video:
    http://www.vegetablegarden.tv/video/xHY ... h-POT.html

    Any one willing to chime in?

    Thanks,
    Bob
    (added links for controller)
    17K Kidney Shaped Pool Concrete (Diamond Bright) Pool, 3/4 hp 2 speed 115V Sta-rite Duraglas PEA5D-180L/P2R5D-181L (Impeller C105-92PS Diffuser C1-216P), 1.5 piping, Pentair CC100 Filter , Heat Siphon 100K BTU Heat Pump Pool Heater, Flow meter Blue White Flowmeter Model No. F-30150P, Hayward Astrolight SP0581N, SWCG CalimarTitanium Edition TE45 , Dolphin Nautilus Plus with CleverClean, Lakeland Florida

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    Brentr's Avatar
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    Re: Homemade Variable Speed Pump

    I would be interested in your findings too.
    6,000 gal, IG free form,Beach Series Antigua by Marbletite Pebble finish,Sheer Descent, IG Fountain, Dolphin / Mermaid Statues,Dura- Glas 1.5hp pump,Hayward Pro-grid DE4820, Aqua Rite SWG with T-Cell 15,Heat Siphon Heat Pump DX 5.0 109,000 btu, Pool Cage, 1800sq ft Tremron Estate Pavers,Aquatherm Ecosun Solar Panels 192 sq ft with GL-235 Controller,Pentair IntelliBrite, Apollo Magnetic Stirrer Our New Poolbuild, Jacksonville, FL yr 2009 Solar install Outdoor kitchen upgrade

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    JasonLion's Avatar
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    Re: Homemade Variable Speed Pump

    That can work. The only issue is how efficient the variable speed controller is. High electrical efficiency at low speeds is not always a primary design criteria for the controllers. Of course, even an inefficient variable speed controller will be way better than a single speed pump, but some are better than others. And none of them can match the efficiency of the IntelliFlo or EcoStar pumps, which use motor designs with higher inherent efficiency than a standard three phase motor.

    If you have an existing pump with a bad motor and are into DIY projects, this can be a great idea. But if you have a working pump or don't have any pump at all, this approach is unlikely to be worth doing in economic terms. Unless your electric rates are very high, replacing a working pump is unlikely to ever pay back the extra investment, and if you are getting a new pump from scratch you will almost always be better off either getting a two speed pump if your electric rates are low or an IntelliFlo/EcoStar if your electric rates are high.

    By the by, there are also variable frequency drive controllers that will work with some single phase motors. If you happen to have the correct kind of motor on hand that can be a better approach than replacing the motor to go the three phase route.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: Homemade Variable Speed Pump

    Do you have three-phase power available? If you don't have it, it might be possible to get, but there might be a charge from the power company to supply it.

    Also, you might need additional power equipment if what you're trying to do induces disruptive harmonics into the power lines.

  5. Back To Top    #5
    JasonLion's Avatar
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    Re: Homemade Variable Speed Pump

    Variable frequency vector controllers are available with single phase inputs and three phase outputs, so there is no need to get three phase power from the power company. The modern ones are also designed to avoid or at least minimize any disruptive harmonics, so that shouldn't be an issue.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

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    bobodaclown's Avatar
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    Re: Homemade Variable Speed Pump

    Quote Originally Posted by JasonLion
    Variable frequency vector controllers are available with single phase inputs and three phase outputs, so there is no need to get three phase power from the power company. The modern ones are also designed to avoid or minimize any disruptive harmonics, so that shouldn't be an issue.
    That was the Variable Frequency Controller that I linked to. It uses 120V single phase they also offer 240V controller also.
    Yeah, definitely a DIY project, but for around $500 a VSP vice a dual speed seems very cool.

    I believe Pentair uses there 3HP impeller on their VSPs. I wonder what the actual motor rating is?
    17K Kidney Shaped Pool Concrete (Diamond Bright) Pool, 3/4 hp 2 speed 115V Sta-rite Duraglas PEA5D-180L/P2R5D-181L (Impeller C105-92PS Diffuser C1-216P), 1.5 piping, Pentair CC100 Filter , Heat Siphon 100K BTU Heat Pump Pool Heater, Flow meter Blue White Flowmeter Model No. F-30150P, Hayward Astrolight SP0581N, SWCG CalimarTitanium Edition TE45 , Dolphin Nautilus Plus with CleverClean, Lakeland Florida

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    mas985's Avatar
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    Re: Homemade Variable Speed Pump

    You need to make sure that the motor is inverter duty otherwise it probably won't last very long. Both the insulation and bearings have to be more robust to handle the harmonics generated by a VFD. Also, this spec "Thermal Protection None" is a problem. I would always have thermal protection on a motor.

    Also, it is a good idea to use a matched sheilded cable to minimize interference to other electrical equipment plus keep the reflected waves from damaging the VFD.

    Next, a Nema 1 enclosure is not rated for outdoors so you may need another enclosure to protect it.

    At one time, I had looked into doing this but quickly found out that to do it right, I was going to be spending close to what a VS cost anyway.
    Mark
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    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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