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0.75Kw Pool Pump on Solar


andrew9484
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Hi,

I would like to put my standard pool pump onto my 2x 5kva Axperts in parallel. The documentation states that the Axpert can operate appliances with motors but i don't see any detailed specifications.

The pump will run during the day so on most days should run directly from solar panels. 

Has anyone done this yet? if not do you foresee any problem?

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On 6/19/2017 at 9:50 PM, pilotfish said:

 Your pool motor is the perfect type of load to run off your 10kVA true sine system. Run it from 9am to 3pm and let the sun pay the bill.

Thank you all! Next question... i would like the pump to only run when sun is shining strong (so it will not drain batteries). I have searched for some type of controller that works on light intensity but found nothing. any other ideas?

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I dont know of a commercially available product but it seems to me it would easy enough to design and build.

It would require an LDR (light dependent resistor) in series with a trim-pot for fine adjustment on one input of an op-amp, with a set voltage on the other input - with the output driving a contactor that controls the pump (in conjunction with the pool timer).

That's the basics - you would need to persuade a propeller-head like Plonkster or someone with electronics background to flesh it out a bit and bang it together.

 

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1 hour ago, andrew9484 said:

Thank you all! Next question... i would like the pump to only run when sun is shining strong (so it will not drain batteries). I have searched for some type of controller that works on light intensity but found nothing. any other ideas?

I have one of these 

http://www.ebay.com/itm/Multi-function-Voltage-control-Relay-Timer-Delay-Switch-Voltage-Protection-12V/271832274268?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

It is very easy to work out at what battery voltage one is starting to discharge. One would need to use the relay's timer so that your pool pump does not continually switch on and off.

I got the idea from SolarJunky.

https://www.youtube.com/watch?v=-lJwHXNtmh4

 

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3 minutes ago, Chris Hobson said:

I have one of these 

http://www.ebay.com/itm/Multi-function-Voltage-control-Relay-Timer-Delay-Switch-Voltage-Protection-12V/271832274268?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

It is very easy to work out at what battery voltage one is starting to discharge. One would need to use the relay's timer so that your pool pump does not continually switch on and off.

I got the idea from SolarJunky.

https://www.youtube.com/watch?v=-lJwHXNtmh4

 

great! thank you

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18 hours ago, pilotfish said:

It would require an LDR (light dependent resistor) in series with a trim-pot for fine adjustment on one input of an op-amp, with a set voltage on the other input - with the output driving a contactor that controls the pump (in conjunction with the pool timer).

Old school analog! I like! Just remember the hysteresis so your contactor doesn't oscillate as it hits the changeover point :-)

Given the cheap prices of small microprocessors, and the time it would take to solder up something using an op-amp, these days you'd probably get a cheap arduino and write ten lines of code :-)

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20 minutes ago, plonkster said:

Old school analog! I like! Just remember the hysteresis so your contactor doesn't oscillate as it hits the changeover point :-)

Given the cheap prices of small microprocessors, and the time it would take to solder up something using an op-amp, these days you'd probably get a cheap arduino and write ten lines of code :-)

Or use a standard off the shelf timer. Mine kicks in at 10am and runs for 4 hours. Works fine every time. 

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1 minute ago, SilverNodashi said:

Or use a standard off the shelf timer. Mine kicks in at 10am and runs for 4 hours. Works fine every time. 

I had a daylight switch once that I tried to modify to work in reverse, turn on when there is light rather than the reverse. Of course the easy way to do it is use a different relay (one with a normally/closed contact) and wire it to that, but I didn't have such a relay and I figured that's not enough of a challenge anyway. So I rewired the divider bridge (LDR on one end, adjustable pot and another resistor on the other end) so that the LDR was on the other side, being careful to stay within the allowed bias voltage of the NPN transistor it was driving.

It worked perfectly on the bench!

What I had forgotten is that I ripped out that daylight switch because it has a weird bug. If there was a power failure after dark, the light would not come back on afterwards. This same bug somehow came back and caused it to fail to turn on unless the change in light level was quick (such as when testing on the bench, but not so much with an actual sunrise).

Aaaanyway... if you're into that sort of thing, you could also rewire a daylight switch.

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14 minutes ago, plonkster said:

I had a daylight switch once that I tried to modify to work in reverse, turn on when there is light rather than the reverse. Of course the easy way to do it is use a different relay (one with a normally/closed contact) and wire it to that, but I didn't have such a relay and I figured that's not enough of a challenge anyway. So I rewired the divider bridge (LDR on one end, adjustable pot and another resistor on the other end) so that the LDR was on the other side, being careful to stay within the allowed bias voltage of the NPN transistor it was driving.

It worked perfectly on the bench!

What I had forgotten is that I ripped out that daylight switch because it has a weird bug. If there was a power failure after dark, the light would not come back on afterwards. This same bug somehow came back and caused it to fail to turn on unless the change in light level was quick (such as when testing on the bench, but not so much with an actual sunrise).

Aaaanyway... if you're into that sort of thing, you could also rewire a daylight switch.

That actually came to mind, for my as well, but I the ones I have also has a weird bug that it takes 10 minutes to turn the light on. This is all fine, in generall, but I found that sometimes when it's cloudy and the sun sets, it's on / off / on / off .... the whole time. And it kept blowing LED bulbs. Hence just using a timer on the pool pump and battery chargers in the garage ;)

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  • 2 months later...

I have three pumps which run off my 5kVA Axpert: 1.5HP for the sprinklers, 0.5HP for fish pond sump pump and 1HP to pump municipal water from a ground tank to an overhead tank. During day time I make sure I run the sump pump to add around 500W load to the inverter so it can pull the free sun energy which would otherwise be idle.

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Isn't an off the shelf timer better? Tracking light intensity may not be ideal. For instance my pond pump runs from 9am to 4pm. I know without a doubt that during this time it will be powered by the sun. There are times when there will be utility power kick-in when solar goes below the load but over and above the sun does justice

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  • 2 years later...
On 2020/02/14 at 10:31 AM, JFox said:

Add a 20w panel (R350) to power 12/24v relay, add 10 ohm resistor (Might change according to relay make), run power to pump via NO connection. Make sure panel points in same direction as PV array

Yeah, liked the idea but it doesn't count for actual usage from other devices.

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  • 1 year later...

Coming back to the original question, I have a pool pump running 4 hours a day on a small pool that draws 650W and 5A (measured using a Sonoff wireless controller). Would it be possible to connect the pump to a PV array using the necessary controller and inverter without connecting to any battery setup?  I know I may be wasting some solar energy whilst the pump is switched off, but this is a first step in trying to take items that run only during the day off the power grid and work out problems etc before going bigger.

Any suggestions re panels, controller and inverter that may be required?

Many thanks

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On 2021/07/28 at 2:29 PM, Waffles KZN said:

Coming back to the original question, I have a pool pump running 4 hours a day on a small pool that draws 650W and 5A (measured using a Sonoff wireless controller). Would it be possible to connect the pump to a PV array using the necessary controller and inverter without connecting to any battery setup?  I know I may be wasting some solar energy whilst the pump is switched off, but this is a first step in trying to take items that run only during the day off the power grid and work out problems etc before going bigger.

Any suggestions re panels, controller and inverter that may be required?

Many thanks

Yes a easy one if you don't have prepaid power. At a minimum a 0.7kW Solis 4g mini grid tied inverter and 2x 400W panels. You can also buy the inverter once up to 2.5kw. Over 2.5kw you need 3-4 panels. No batteries and only connect AC to the inverter when the timer starts the pump. No controller needed as the MPPT is part of the inverter. 

A bit of a waste but will still provide the power saving on full sunshine days and contribute on other days by using from the grid what the panels cant supply. 

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  • 3 months later...
4 hours ago, Shonnay said:

Hello,

I have a Quality pump-model QP/03 - 0.75kw

Is it possible to convert this pump to solar?

Its a 50000lt pool.

Thank you in advance.

Shonnay 

My 2c is yes. Use about 800W of panels and connect them to a grid tied inverter like a Solis mini 4G. Set pump to run during the peak period of 11h30 to 14h00. Solis is only connected to grid when the pump gets 220V. When PV is lower than 750W you just draw the rest from the grid. No batteries to manage. 

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On 2017/06/26 at 4:36 PM, andrew9484 said:

Thank you all! Next question... i would like the pump to only run when sun is shining strong (so it will not drain batteries). I have searched for some type of controller that works on light intensity but found nothing. any other ideas?

I use Home Assistant together with a smart breaker switch to decide whether to switch my pool pump on or not.

Home Assistant comes with a solar forecasting module that can predict your solar production for the next day. My system forecasts on average, about 50kw/hr production, if it is forecast to produce less that 25kw/hr for the day I don't turn the pool pump on in the morning. 

https://www.home-assistant.io/integrations/forecast_solar/

I use node red to check the forecast production for the dat at 08:00 and if it is above 25kw/hr it switches the pump on using the smart breaker switch. Otherwise it leaves it off. It switches the pump off at 15:00 everyday.  I can also switch the pump on/off manually from my phone

Very easy to do.

 

 

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