140’ well, water level at 20’, how deep to put my 12v pump?

[James Hird]

Hi, I’m new to the fourm.

Installing a 12vdc pump (10a max current) in my 140’ well.

I’ve only got 100’ of 10awg wire. The voltage drop is crazy if I use this, something like 17%.

I can’t afford to buy 6awg wire which I think it needs.

The water level in the well is 20’ below the surface. The pumps max flow rate is 3.6gpm.

What is stopping me from putting my pump at 50’ down the well. Doubling up on the 10awg wire to get an equivalent of around 7awg.

I solve my voltage drop problem by reducing the length of the conductor by half and doubling the thickness of it.

Are there any problems having a pump this size in the middle of the well. It only pumps 3 or 4 gpm. The well was producing 30+gpm when it was drilled. It was flowing to fast to measure. The guy thought it might go artesian.

Another option I though of was to get a 24v pump. Higher voltage, less amps. I’ve already bought the 22v pump though and it’s past the 30day return policy.

Thanks in advance,

James

 

[Valveman]

What 12V pump do you have? It is rare for a 12V pump to work from that deep.

 

[Sponsor]

 

[Reach4]

Installing a 12vdc pump (10a max current) in my 140’ well.

I’ve only got 100’ of 10awg wire. The voltage drop is crazy if I use this, something like 17%.

If you double up, you would need 200 ft of #10 to put your pump 50 ft down.

But putting the pump 25 ft down would work if the water level stays above the pump.

 

[LLigetfa]

Are there any problems having a pump this size in the middle of the well. It only pumps 3 or 4 gpm. The well was producing 30+gpm when it was drilled. It was flowing to fast to measure. The guy thought it might go artesian.

If the well produces that much, the only reason to set it much lower is if the static water level drops. Doubling or quadrupling the wire would be challenging to ensure a water-tight seal on the splice. I suggest breaking open the piggy bank and getting the right gauge of wire.

 

[Valveman]

Again, will the pump even produce from 50'?

 

[James Hird]

What 12V pump do you have? It is rare for a 12V pump to work from that deep.

Here's a photo of it.

12v
10amps
230ft lift
100ft max depth

Does anyone have any experience with this pump?

 

[James Hird]

If you double up, you would need 200 ft of #10 to put your pump 50 ft down.

But putting the pump 25 ft down would work if the water level stays above the pump.

Sorry, I should have being more clear about wire I have got.

Its 100ft of 3 core #10, so technically I've got 300ft of #10

 

[James Hird]

Again, will the pump even produce from 50'?

I was considering cutting the wire that I have (100' #10/3 in half and using each 50ft length on the positive and negative.

Three #10 wires combined is equivalent to one #5 wire. which I don't think exists so round it up to #6.

According to southwire.com volt drop calculator. A #6 wire can supply 10 amps on a 12v system 57', this is allowing a 4% (0.48v) voltage drop.

I think it should work.

 

[James Hird]

Again, will the pump even produce from 50'?

I was considering cutting the wire that I have (100' #10/3 in half and using each 50ft length on the positive and negative.

Three #10 wires combined is equivalent to one #5 wire. which I don't think exists so round it up to #6.

According to southwire.com volt drop calculator. A #6 wire can supply 10 amps on a 12v system 57', this is allowing a 4% (0.48v) voltage drop.

I think it should work.

 

[James Hird]

If the well produces that much, the only reason to set it much lower is if the static water level drops. Doubling or quadrupling the wire would be challenging to ensure a water-tight seal on the splice. I suggest breaking open the piggy bank and getting the right gauge of wire.

I'll be keeping a close eye on the static water level this summer. that's why I'm reluctant to break open the piggy bank just yet.

If the water stays around the 20' mark year round then having my pump at 50' will be fine.

If not then I'll have to go deeper and with a different pump, maybe 24v.

Do you know a good source for well wire?

 

[Valveman]

That is a very interesting pump. I can't find much info on it, but I assume it is a piston or diaphragm pump. Coupled with a DC I wouldn't expect them to last very long, but still a cool idea. With DC it is all about the voltage. Gotta have large enough wire to keep the voltage drop down or the pump just doesn't run at full speed.

 

[James Hird]

That is a very interesting pump. I can't find much info on it, but I assume it is a piston or diaphragm pump. Coupled with a DC I wouldn't expect them to last very long, but still a cool idea. With DC it is all about the voltage. Gotta have large enough wire to keep the voltage drop down or the pump just doesn't run at full speed.

I found the exact same pump but 24v. This should solve all my wire sizing issues.

It only pulls 5amps so with #10 wire the run can be 70’ with a 3% voltage drop (0.72v)

The pump looks exactly the same as the 12v one I’ve got. It’s sold by a different company though so a different label

https://www.amazon.com/ECO-WORTHY-Stainless-Solar-Powered-Submersible/dp/B073Y8H3LC/ref=mp_s_a_1_3?keywords=eco-worthy+24v+well+pump&qid=1675297563&sr=8-3

I’m not sure about the longevity of it. There were mixed reviews but for the price tag I think it’s worth a shot.