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Forum Index : Electronics : Pool pump on VFD
| Author | Message | ||||
| noneyabussiness Guru  Joined: 31/07/2017 Location: AustraliaPosts: 513 |
Morning all, just a curious question, anyone have experience with a 1kw ish pool pump slowing it down with a vfd to drop it current requirements. .. there is a commercial version (pool pump VFD ), a glorified VFD setup for them... i can build the vfd or purchase cheaply, but im unsure what to look for when slowing it down etc.. Obviously pressure output and heat in the motor itself are 2 signs but i thought I would pose the question to the gurus on here ... I think it works !! |
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| Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1664 |
If you could stick a flow meter in the water line you may be able to calculate the most efficient pump speed in terms of flow rate Vs Wattage used. Maybe calculating something like Litres per kWh or kWh/MegaLitre etc. Cheers. |
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Ralph2k6 Senior Member  Joined: 24/09/2017 Location: AustraliaPosts: 129 |
Sorry no personal experience with pool pumps in particular. But you are on the mark with regard to observing heat rise due to reduced cooling fan speed. Many reasonable vfds have built in thermal profiles for motor loads to determine and prevent overheating. Are you buying an off the shelf vfd or actually building your own vfd? Ralph |
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| noneyabussiness Guru Joined: 31/07/2017 Location: AustraliaPosts: 513 |
Thanls for your replies so far, im happy to build one, they actually don't look overly difficult. . Heck our eg8010 could happly suffice... just more the curves for this particular job.. Its internally fan cooled if that helps... I think it works !! |
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Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1026 |
Interesting? Made me have a look around. I did experiment with frequency on a single phase motor using a little inverter I built. The motor was not happy with more than 5Hz either side of 50Hz that it was designed for, After looking at This web page I can see why, Few motors will work, most wont by the looks of. Makes me wonder what is in that pool pump drive? Would be more than a usual VFD? Had fun with the 3 Phase motors on a VFD, I have run them down to just a few Hz on a fan. Cheers Aaron Off The Grid |
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| noneyabussiness Guru Joined: 31/07/2017 Location: AustraliaPosts: 513 |
I do know any cap start or soft start motors are almost a no go ... they may slip into there start cycle too much and burn it out .. the pump i have ( and apparently a lot are the same ) have none of the above.. and is well suited to vfd control... thank you for that article, it was very interesting. . Im going to do a oz, and suck it and see i think... no just gotta get the time to do said effort.. I think it works !! |
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renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
would one of these work ? I used to use one to control the speed of a motor that was hooked up to a gearbox, then to fine tune the speed it could adjust the freq. Probably is still in my shed somewhere, can't remember seeing it recently though. Cheers Caveman Mark Off grid eastern Melb |
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| Ralph2k6 Senior Member Joined: 24/09/2017 Location: AustraliaPosts: 129 |
I see on the glossy brochure at 'future wave' you linked to, they indicated just running the pump at about 31hz. Yes Mark that SEW unit would likely do the job. There are numerous little 1 phase open chassis drives around that could be put into an enclosure. No fancy screens but simple set and forget adjustment pots. Ralph |
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| johnmc Senior Member Joined: 21/01/2011 Location: AustraliaPosts: 282 |
I thought VFD only work on 3 phase motors. cheers john johnmc |
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yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
This is always the problem with DIY stuff, we just stagger around till we find what we need to know. Sometimes it is quick other times it takes a lifetime to find the missing pieces. pumps and fans should have an advantage because the torque needed increases dramatically with rpm, however sometimes it feels like the torque hits a brick wall at low revs with single phase. some controllers have vectoring?? and variable torque and constant torque modes for different applications. they also have adjustable amp limiting built in to prevent cookage. I still haven't worked out what to do with the various chokes and braking resistors yet. I do know that silicon chip mag has done a induction motor speed controller back in Apr/may 2012 and an update in Aug 2013 and the programmed PIC and PCB is available for about 50 bucks, I dont know if it is suitable and I dont recall the size limit of the motor. I'm confused, no wait... maybe I'm not... |
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Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
In the EG8010 manual, there is a number of examples there that could easily be adapted via rectified AC. The variable frequency (and voltage) is already built into it, there won't be any need for a big transformer. This is probably what NYB has in mind. There are only 10 types of people in the world: those who understand binary, and those who don't. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
These are totally enclosed fan cooled induction motors. Why not remove the fan at the back and fit a pulley in its place. Then use belt drive from a higher rpm brush type ac/dc motor that can much more easily be speed controlled. Cheers, Tony. |
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