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Inverter for Pool Pump

Posted: Tue, 03 Apr 2012, 00:25
by bidgeeeman
Hi.
Can anyone tell me if it is possible to run a 240 volt pool pump from a 12 Volt lead acid battery or a bank of them? I got a pump given to me and have hooked it up to my 5000 lt rainwater tank. Currently it's drawing from the grid but it would be great to run the pump from a solar rechargeable 12 battery or 2. Only needs to run for 10-15 minutes just for
watering the garden.

Any ideas/suggestions?
Cheers
Bidge   

Inverter for Pool Pump

Posted: Tue, 03 Apr 2012, 01:56
by Adverse Effects
you would need an inverter

Inverter for Pool Pump

Posted: Tue, 03 Apr 2012, 02:00
by bidgeeeman
Hi.
Thanks for the response. I thought i would need an inverter. Can anyone suggest one that would do the job? Is there anything else I would need for this setup?

Thanks
Bidge

Inverter for Pool Pump

Posted: Tue, 03 Apr 2012, 04:28
by coulomb
bidgeeeman wrote: Can anyone suggest one that would do the job?

Check the power rating of the pump; it might be say 400 W. But the turn on surge will be large; at least twice that. So you'd need an inverter with a pretty good surge rating, say 800 - 1000 W surge.

The current draw during start-up (and it will spend maybe 5% of its life doing start-up) will be huge on the DC side, so I'd suggest a 24 V battery and inverter, to keep the current draw below say 100 A (during start-up). The batteries will need to be stout, too; not 6 Ah gels (though they won't need much actual energy capacity, just power capability). Two small old car batteries would possibly do it.

Edit: I forgot the pure verses modified sine wave question. I suspect for this, you could get away with a cheap modified sine wave inverter; it would be good to be able to borrow one to try it out. The motor (likely a "single phase" induction motor) will prefer pure sine waves, and the control circuitry will possibly require it. I think you might have to use trial and error.

Inverter for Pool Pump

Posted: Tue, 03 Apr 2012, 05:44
by bidgeeeman
Thanks for that very informative answer. If things work out with this project I might even try my hand at a bank of batteries to run our pool pump as well.

Cheers
Bidge

Inverter for Pool Pump

Posted: Sat, 07 Apr 2012, 01:53
by antiscab
is the pool pump single or 3-phase?

if 3-phase, you could use a variable frequency drive and 50 x 7Ah SLA

3kw vfd brand new is like $300

batteries cost depends more upon capacity than number or voltage

Matt

Inverter for Pool Pump

Posted: Sat, 07 Apr 2012, 01:59
by bidgeeeman
Hi.
Not sure if the pump is 3 phase or single as it was given to me.....but....since my last post I have phoned a couple solar power places for advice and they basically told me to forget battery power and go with a solar power system as this will offset the cost of running a pump???? Also one guy I spoke to said an inverter powerfull enough to start the pump and run it would cost me up to $2000.00????

Now I am confused
Bidge

Inverter for Pool Pump

Posted: Sat, 07 Apr 2012, 07:33
by antiscab
unless you really want to be able to run the pump during a black out, then yes you are best off running it from the grid, and getting a solar system to put electricity onto the grid.

an inverter has to supply the full surge current to start the pump.
depending upon the pump, this can be rather large, meaning you need a big inverter

what does the name plate on the pump say?

Matt

Inverter for Pool Pump

Posted: Sat, 07 Apr 2012, 15:09
by Tony23
hi bud, i have a 'rule' 12v bilge pump from a boat in my 1000ltr rainwater tank on my shed, i have an old jetski battery, bout 14ah, gets charged by a little 5w solar charger, i just have the pump feed a sink in the shed, i fill bucket or watering can then water potplants etc...
im sure u could make a much bigger\stronger system, my pump is only rated at 360gal\hr, much bigger ones are available, & then u could ad bigger batteries & solar panel etc....hope that gives u some ideas.

ps, i also use another pump the same in my koi pond, connected to small filter, this pump runs direct from a 20w bp solar panel, had this setup for years, only obviously works when sun is out, but just helps water circulation\aeration etc.

cheers.

Inverter for Pool Pump

Posted: Sat, 07 Apr 2012, 15:33
by bidgeeeman

Heres a photo of the plate on the pump.
Image



Nice suggestion on the 12 volt pump. :)
Might look into that. It's just that this one was given to me and i have been wanting to get into a solar project for a while and using it as a bit of an excuse really. I am not very knowlegable about all this but want to learn.

Thanks
Bidge

Inverter for Pool Pump

Posted: Sun, 08 Apr 2012, 05:05
by coulomb
bidgeeeman wrote:
Here's a photo of the plate on the pump.

Ok, 680 W; the 400 W I mentioned was for my rainwater pump. I'd say that the 5.5 A is the maximum startup current, possibly at 250 V. That would be 240 x 5.5 = 1320 VA, so you'd want an inverter with say a 1500 W surge rating. That's getting up there, especially if you decide on a pure sine wave inverter. I see that Jaycar have pure sine wave inverters these days, as well as the modified sine wave (cheaper) ones.

A Jaycar 1000W continuous pure sine wave inverter is $600:

http://jaycar.com.au/productView.asp?ID ... rm=KEYWORD

The 600 W model only has a 1000 W surge rating, so it likely won't start your pump.

The modified sine wave model is much cheaper at under $200:

http://jaycar.com.au/productView.asp?ID ... rm=KEYWORD

I guess it wasn't all that long ago that a 1000 W continuous sine wave inverter would have cost $2000.

Inverter for Pool Pump

Posted: Sun, 08 Apr 2012, 14:35
by bidgeeeman
Thank you so much for the advice and the links!
So are you saying I could get away with the modified sine wave model for under $200?

Cheers
Bidge

Inverter for Pool Pump

Posted: Sun, 08 Apr 2012, 15:27
by coulomb
bidgeeeman wrote: So are you saying I could get away with the modified sine wave model for under $200?

I don't know. I would think that an induction motor would perform better with pure sine waves; otherwise, the back EMF would be wrong most of the time. The inductance of the motor will smooth the current fluctuations a little, but I suspect not enough. For a low duty cycle application like a rain-water pump, you could maybe get away with it. For a pool pump, which runs for hours, I'd suspect you'd need a pure sine wave inverter.

I was hoping for others to report their experiences with induction motors on inverters.

Inverter for Pool Pump

Posted: Sun, 08 Apr 2012, 15:44
by bidgeeeman
No problem....there maybe some more responses to this thread to come then.

BTW Happy Easter to you all!

Cheers
Bidge

Inverter for Pool Pump

Posted: Thu, 12 Apr 2012, 06:12
by rjws
A 'Modified Sine wave" (read 'Pulse wave' or more correctly, 'modified square wave') inverter will make your motor run about seven to ten percent hotter than it otherwise might do.Image   This will impact on its life-span a little, but since it cost nothing, then, well ....Image In the greater scheme of things, you might be better off using a DC pump running from your solar panels/battery. They have power optimising controllers that make the most of available sunlight and are commonly used in agricultural areas to replace old windmills. Look up 'Solar Pumping' or similar.
RJWS

Inverter for Pool Pump

Posted: Thu, 12 Apr 2012, 15:13
by weber
Or convert your pool to biological-plus-UVC filtration and use an axial (propeller) pump in the pool and run it directly off a single 60 watt solar panel with no battery. See
http://groups.yahoo.com/group/swimming-ponds/

Oops. Should have re-read original post and not relied on thread title. I see it's not for a swimming pool but for watering the garden from a rainwater tank.

See instead, another ReNew magazine article of mine from pages 27-28 of issue 95 (Apr-Jun 2006), "Low cost pumping for the garden". An elegant 12 V bilge pump conversion.
http://shop.ata.org.au/cart.php?target= ... t_id=16400

[Edit: Realised wasn't for pool, added the rest]

Inverter for Pool Pump

Posted: Thu, 05 Dec 2013, 04:07
by offgridQLD
Old thread but just a idea. If you want a good value pure sine inverter go searching for 2nd hand UPS on ebay and the like. I just picked up a 3000w pure sine UPS with 175A Anderson input at the back for a external 48v battery bank input all for just $100 cash.

Image

Image


Lots of largish offices just toss old UPS out when the internal battery's are dead or they are upgrading there system. The commercial ones 3kw and above are very beefy mine was 35kg without the battery's and can handle some reasonably big loads.

As a cost comparison my 6kw continuous pure sine inverter for my house has a RRP cost to $8,000 An old UPS isn't as good but for the money they go for 2nd hand by comparison they are amazing value and have a very clean output often better than the grid. The fans can be a little noisy as they are designed to be in a hot wrack with other components but you can slow the fans down a lot and they still stay cool when out in the open


After removing all the dead 7ah lead acid batterys from the case.I hooked a tiny little 48v 5ah lithium battery to the front Anderson plug. I pluged a 2400w espresso machine into the back and had no trouble making a coffee while powering a 800w toaster at the same time. (would have been better through the rear 175A Anderson but just to test it worked it was fine.
Image

Inverter for Pool Pump

Posted: Thu, 05 Dec 2013, 06:24
by acmotor
yeah, old thread, when you posted it popped up again.Image

That davey pump is a 'split phase' capacitor run item that, as RJWS pointed out, should be run on a pure sine inverter. The harmonics in modified sine wave result in high capacitor currents. I have a same pump and it will start off a 1kW pure sine inverter.

A 12V pump is probably not an option as that davey is maybe 200 litres per minute at 50kPa. Typical 12V pumps will be 10-20 litres per minute at 300 kPa.

Kurt, does that APC UPS have the ethernet module ? I have 1000VA version but haven't located software yet. netclient or something.

Good comment about the second hand office UPSs ! Just be careful, many are not continuous rated, being only designed for 5 or 10 minutes. That particular APC is continuous though the idle power is maybe 120W in bypass and as much as 200W in inverter mode. Efficiency was not the intention.

Inverter for Pool Pump

Posted: Thu, 05 Dec 2013, 13:31
by bidgeeeman
Hey....Love that post on the reworked UPS!! Updating the original post I made....the old Davey had shot bearings and ended up being pretty useless as it just froze and was'nt worth fixing.I now run a small 12v bilge pump hooked to the garden hgose and it actually gives me just enough pressure to water the vegies nicely.

Cheers
Bidge

Inverter for Pool Pump

Posted: Thu, 05 Dec 2013, 15:38
by offgridQLD
Good to see you get a pump sorted out that dose the job. Watering gardens doesn't need a lot of pressure or volume. Just need to get the water to were you want it slowly and let it soak in without erosion.

Acmotor, That UPS has the Ethernet option but mine wasn't fitted with it. There is just a blanking box there with a ribbon cable going to it. I do have a copy of the software. You don't need Ethernet to make changes to the UPS default settings. There is a USB port (A serial port labeled as USB) I have a little adapter. All the set points can be adjust through that with a PC.

You made two good points. One the UPS at idle isn't that efficient. Some are better than others.In the photo of my UPS in my previous post you can see a little inline current shunt on the battery leads. I measured this one at 90w inverter mode but then it would ramp up to 180w then back down to 90w slowly over a few seconds. (not sure why that is?) Anyhow the consumption was as expected. They wouldn't make the most efficient 24/7 off grid inverter consuming 2 - 3kwh a day doing nothing. My intention was just to use it a turn on to do a task and then switch off again. What that task is I'm not sure. Perhaps charge the Imiev, I didn't really need it but I cant resist this kind of thing at a good priceImage

The second good point you made was continuous rating.Most small UPS that just have a few 7AH batterys internally and no option to conect external battery banks are usually just designed to run for 10min or less at full load. Look for one that has a large Anderson plug at the back. The one I got is designed to have up to ten large external banks daisy chained in parallel for long operation times. Usually if a inverter can run a load for 1hr then it's heat soaked enough that it will do it continuously without issue.

A good sign of the surge capacity is the size and amount of capacitors on the board. The UPs has 3 reasonable size capacitors but nothing compared to my selectronics inverter that has a Forrest of 16 large caps and can start a 3hp air compressor simultaneously with a 200A welder or 50A plasma cutter (I have seen some crazy spikes on the logs when i get carried away in the workshop)

Guts of the selectronics, with Forrest of caps on a ultra low impedance
4oz copper circuit board. Behind that there is over 60kg!of torriod transformer you get what you pay for.
Image

I would say the UPS could start a fridge or small AC unit no problem, I haven't tested its limits about 3200w is all I have taken from it to date.

Perhaps one of the transformers in the UPS is for charging the batterys and isn't needed? If it wasn't so dam heavy I would install it in my UTE full time.

Back to the pumps. The design and quality of a pump plays a big part to its efficacy. We have a 240v pressure pump (cant remember the brand but is a good one) At our off grid house it has a good positive pressure freed from the tank above it and nice size lines in and out to reduce help but even so its very efficient for its output 400w is a typical consumption for it and it has to pump the full length of the house to laundry and outdoor taps at the other end up to 50m one end to the other. The pressure even at the other end is above that of the mains pressure in our city house.

Image

The other end of the scale we have a nasty Aldi $80 pump on a tank at our city house and that consumes a continuous 1000w and its output is way less than the other pump mentioned above.
Image

Kurt


Re: Inverter for Pool Pump

Posted: Thu, 14 Jun 2018, 18:19
by Richard22
Hey,

I am new to this forum and I want to know about pool pump inverter, how can installed a new inverter on to the existing pool pump.
Please suggest me some installation tips about it.????
Thank you in advance.

Re: Inverter for Pool Pump

Posted: Tue, 26 Jun 2018, 14:28
by fin21
Hi,

Is it good to use the solar pump for swimming pools??

Thanks

Re: Inverter for Pool Pump

Posted: Wed, 05 Dec 2018, 01:29
by ovion21
Hello Everyone,

Pool Inverter is a low-cost solution designed to greatly reduce the running costs of pool circulation pumps and improve the efficiency of swimming pool filtration. Pools’ low capital outlay ensures that the typical capital payback period is less than 2 years. Swimming pool pumps invariably run at higher flow rates than necessary. Pool Inverter technology enables you to control both pump flow-rates and pump run times. Pool transforms conventional pool circulation pumps into ‘variable speed’ pumps resulting in huge savings in energy costs.

Thanks