Switch - Water pump - Inverter

Johannlog

New Member
Hi, I am looking to set up a system to pump water from my well using a 220v ( about 6.5a) water pump (400' + deep) I have 6x100w panels and a 206ah SOK Battery and have ordered another 200ah battery...
I would like suggestions on a 12v or 24v inverter to use for this.
I am thinking it would be best to only have the pump turn on when the sun is out so it doesn't use up the battery, what is the name of the switch I would use for this?
Thanks
 

rcrracer

Solar Enthusiast
2 pole contactor with 120v ac coil https://www.amazon.com/Packard-C230...refix=packard+2+pole+contactor,aps,236&sr=8-5 and a photo cell https://www.amazon.com/120-Volt-Out...words=Photocell+Sensor&qid=1620155170&sr=8-37 and a 120v coil relay https://www.amazon.com/uxcell-HH53P...0v+coil+Relay+and+Base&qid=1620155670&sr=8-33. Photo cell turns closes switch at night. The opposite of what you want. Wiring photocell switched red wire to relay coil along with a neutral will energize the relay. Wire contactor coil to relay's NC contacts.
Much easier to just use a pool pump timer and forget about sun in/out. https://www.amazon.com/Woods-59104R...11&sprefix=intermatic+t104+p+,aps,221&sr=8-11. Something like an Intermatic T-104P. You can take parts from first idea & second idea, and use the photocell.
 

Johannlog

New Member
2 pole contactor with 120v ac coil https://www.amazon.com/Packard-C230B-Pole-Contactor-Voltage/dp/B001KGSJ74/ref=sr_1_5?crid=OMZY49QCLWAT&dchild=1&keywords=packard+contactor+2+pole+240v&qid=1620155038&sprefix=packard+2+pole+contactor,aps,236&sr=8-5 and a photo cell https://www.amazon.com/120-Volt-Out...words=Photocell+Sensor&qid=1620155170&sr=8-37 and a 120v coil relay https://www.amazon.com/uxcell-HH53P...0v+coil+Relay+and+Base&qid=1620155670&sr=8-33. Photo cell turns closes switch at night. The opposite of what you want. Wiring photocell switched red wire to relay coil along with a neutral will energize the relay. Wire contactor coil to relay's NC contacts.
Much easier to just use a pool pump timer and forget about sun in/out. https://www.amazon.com/Woods-59104RWD-Outdoor-24-Hour-Mechanical/dp/B0076CQY3M/ref=sr_1_11?crid=FA2AQ2OQVFF1&dchild=1&keywords=intermatic+t104p+dpst&qid=1620156325&refinements=p_36:2200-&rnid=1243644011&sprefix=intermatic+t104+p+,aps,221&sr=8-11. Something like an Intermatic T-104P. You can take parts from first idea & second idea, and use the photocell.
thanks
 

rcrracer

Solar Enthusiast
I left something out. If you use a photocell, on the 120v control circuit hot/phase conductor, you should add something like a three way switch. Attach the 120v hot to the com. screw. Run a wire from one of the traveler screws to the contactor coil. Run a wire from the other traveler screw to the photocell/relay circuit, and then to the contactor coil. This allows a means to over ride the photocell path and manually turn the pump on.
There has has to be a better way to do all this. This is an old school way.
 

Bud Martin

Solar Addict
Are you going to get inverter with the ON/OFF remote port that only requires close contact to turn on the inverter and open contact to turn off inverter?
Turning on and off the 120VAC output of the inverter to the load is not a efficient way since the inverter is still running (in standby no AC load) and will still draw current from battery, it is better to turn off the inverter via remote connection.
But also the question is, is the inverter providing power to the other loads as well when the pump is not used, if it does then turning inverter on and off is not applied so go with switching the power to the pump instead.
 

Johannlog

New Member
Are you going to get inverter with the ON/OFF remote port that only requires close contact to turn on the inverter and open contact to turn off inverter?
Turning on and off the 120VAC output of the inverter to the load is not a efficient way since the inverter is still running (in standby no AC load) and will still draw current from battery, it is better to turn off the inverter via remote connection.
But also the question is, is the inverter providing power to the other loads as well when the pump is not used, if it does then turning inverter on and off is not applied so go with switching the power to the pump instead.
You bring up some good points. I am thinking this through. 1. I don't need the pump to run all the time, it is just filling a gravity storage tank. So I could just manually turn it on and off and it sounds like that would be a whole lot simpler. It is a 220v Pump (3/4 horse I believe) with soft start.
I don't yet have a 220v inverter - if you have suggestions as to which I should be that would be helpful, or maybe I should do a no battery system?
 

Woody

Solar Addict
A domestic 400+ ft water well is in the deep well category. I had looked into doing this but a bit deeper at 500ft level well with static just over 350ft. I was cautioned by the well drillers/installers not to go solar due to the power needs. In looking at solar water pump dealers they too cautioned against using solar for deep wells. They typically stated one should consider using a generator instead. As such, I went with a diesel generator.

My initial thoughts on the inverter and battery bank would be to oversized them. Use a Low Frequency inverter and not a high frequency one. 24v battery bank is a decent starting point but might consider going 48v. I’d skip the 12v implementation. Too much DC amps moving about with a 12v system. Plus, you have a long AC line going down the hole to the pump. Voltage sags and current goes up on long wire runs. Thats why I’d go a bit on the oversized inverter, battery bank, and wire size going to the pump.

I’m eager to hear how this works out for you. Please update this forum accordingly. If it works out really well for you, well I might have a new project to take on for my emergency water implementation needs.
 

A.Justice

Swears he didn't start that fire.
Maybe something along this line?
I can't speak highly enough of Intermatic timers. I work on swimming pools and they mostly use them. The wood post that they are attached to will likely rot out of the ground before those things stop ticking. They rarely fail.
 

MarkSolar

New Member
A friend has a 600' well and got his pump from this place. He uses it for livestock, during the day he fills up a couple of storage tanks then uses a small pump to transfer water into the troughs. I'm pretty sure he doesn't have an inverter, but don't know the details on how he runs the pump.
 

MichaelK

Photon Sorcerer
Hi, I am looking to set up a system to pump water from my well using a 220v ( about 6.5a) water pump (400' + deep) I have 6x100w panels and a 206ah SOK Battery and have ordered another 200ah battery...
I would like suggestions on a 12v or 24v inverter to use for this.
I am thinking it would be best to only have the pump turn on when the sun is out so it doesn't use up the battery, what is the name of the switch I would use for this?
Thanks
I'm sorry, but I think you are going to get a really bad reality check. This system might not even get the pump started, let along keep it running for any significant amount of time.

Too small a battery, and FAR too few solar panels. I'm speaking from experience here, having successfully running a 240VAC pump for years now.

Here is what you really need. Let's assume your pump needs 6.5A at 240VAC, which works out to be 1560W, running. Let's assume your starting wattage is 3.8X, which is what my pump's starting ratio is. So you need 1560W X 3.8X = 5920W at startup. So, an inverter that an surge to 6000+W for >1 second (1000 ms).

A good rule of thumb is you need 2X the number of panels for the load you want to run. So, for a 1560W load you need 1560W X 2X = 3120W of panels.

For batteries, you need to have at least 8X capacity for lead-acid, and 4X for lithium. So, with a 24V system that works out to be...
Pb: (1560W/24V) X 8X = 520Ah battery
Li: (1560W/24V) X 4X = 260Ah battery

So what you need is ~3000W of panels, a 260-520Ah battery bank, and an 120/240 split-phase inverter that can surge to 6000W. Take a look at the Conext 4024. I use that for my workshop.

BTW, my 48V system, with 4500W of panels and 375Ah battery can run my 1hp 240VAC pump from 8am to 4pm throughout the whole growing season.
 

mike95490

Solar Enthusiast
The following chart applies to most AC powered well pumps. Franklin makes the motors, and all the motors in the same class, consume the same starting and running power.
Locked rotor amps is what your inverter will have to provide for about 2 seconds to get the pump running. 12V & 24V systems will have a rough time because of copper losses in the DC wiring.

As an example, my XW inverter logs my 1/2 hp 3 wire pump at 1,000 watts running. That includes PF losses, and everything.

Well Pump Motor Specs.jpg
 
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