Distance between panels and controller

[DannyG]

My panel 48v 730w mono is about 100m away from my controller/pump 550w dc. The controller has a mppt. I am using 4mm solar cable. I am then using 1 inch pipe trying to run the water about 6 meters up over a 100 meter distance. In midday sun, I am able to pump water, but not when I attach the outtake pipe. It seems to just run but not actually push any water out. The controller is saying it's at about 1950 rpm, 38v , 4 amp and 150 to 170 w.

What's the biggest issue? The panel to controller distance? I can maybe shorten it to 85 or 90 meter

How can I test the solar panel to see what it's output is?

 

[DIYrich]

What's the biggest issue? The panel to controller distance? I can maybe shorten it to 85 or 90 meter

biggest problem: 730w panel trying to power a 550w pump. The panel outputs 730 watts under ideal conditions. Midday in Thailand can get pretty close.

Second problem is sending 15 amps through 4mm (12 awg) wire over 100 meters. You are loosing 35% of the power (voltage drop).

Try adding a 2nd panel. Series if your controller can handle the voltage. If parallel, then you will need to upgrade the wire.

Shortening by 10 meters (10%) won't help significantly enough.

 

[AshleyL]

He forgot to account for the power surge + actual power consumption (reactive + active = apparent power).........assuming if the pump is running on AC power.

Difference Between Active Power, Reactive Power and Apparent Power – Schneider Electric

Understand electricity basics: Active Power is real energy, Reactive Power affects voltage, and Apparent Power is the total power. Simplifying the differences for easy comprehension.

eshop.se.com

Active Power is real energy, Reactive Power affects voltage, and Apparent Power is the total power.

 

[OzSolar]

What's the biggest issue? The panel to controller distance? I can maybe shorten it to 85 or 90 meter

It could be many things but it sounds to me like you are exceeding the the TDH of your pump.

How much is pumping without the outtake pipe hooked up? Close to what it's rated at?

 

[DannyG]

Thank you everyone for your replies. I shortened it by about 15 m but that didn't seem to make a significant difference.

I'm thinking that cutting down some trees to open space closer to the pump is my best and maybe only solution.

It is DC power all the way. Panel, controller, pump.
Pump is 550w dc designed and is supposed to be able to pump 24m up and 6000litres per hour under ideal conditions. 1" inlet/outlet.

 

[AshleyL]

Thank you everyone for your replies. I shortened it by about 15 m but that didn't seem to make a significant difference.

I'm thinking that cutting down some trees to open space closer to the pump is my best and maybe only solution.

It is DC power all the way. Panel, controller, pump.
Pump is 550w dc designed and is supposed to be able to pump 24m up and 6000litres per hour under ideal conditions. 1" inlet/outlet.

You are going to need a battery as buffer either way.
Just because the pump is DC-based doesn't mean there is no surge.

 

[OzSolar]

You are going to need a battery as buffer either way.
Just because the pump is DC-based doesn't mean there is no surge.

Actually it does. The typical DC well pump and controller combination have no surge. They are specifically designed to not be used in conjunction with batteries and just pump when the sun shines. There is no surge on the dozens I've used.

 

[OzSolar]

It is DC power all the way. Panel, controller, pump.
Pump is 550w dc designed and is supposed to be able to pump 24m up and 6000litres per hour under ideal conditions. 1" inlet/outlet.

Link to the pump specs?

Did you test the flow as close to the pump as you can?

All of the solar pumps I've been around are very sensitive to getting the proper voltage. Too low and they won't work at at. Voltage is more important to be able to pump and then pumping at the full rating requires the full wattage.

 

[DIYrich]

I'm thinking that cutting down some trees to open space closer to the pump is my best and maybe only solution.

I would try adding a second panel before cutting down trees.

 

[DannyG]

Link to the pump specs?

Did you test the flow as close to the pump as you can?

All of the solar pumps I've been around are very sensitive to getting the proper voltage. Too low and they won't work at at. Voltage is more important to be able to pump and then pumping at the full rating requires the full wattage.

I cut down the trees ("invasive" pioneer trees I was going to cut anyway), and shortened the wire from solar panel to the controller/pump from 90m to 15m. There was little additional power. The controller was saying 40 volts, 4. Something amps and around 170 plus watts. Before it was 38/3.8/150 or so. I'm still not certain how to test the panel. My assumption at this point is the quick snap solar connectors. I've had that be an issue for my home setup (1 panel, 1 12v battery).
Curiously, the mppt light wasn't flashing anymore after I moved the panel and re set everything up. That worries me too.
I've attached pictures of the panel and controller. Couldn't take a picture of the pump but it says 48v 550w dc solar pump.
Thanks again everybody

 

[littleharbor2]

Your panel's voltage is too low. A second panel in series should fix your problem.

 

[DannyG]

Your panel's voltage is too low. A second panel in series should fix your problem.

Thanks. I see now that it is rated at 41 v , not 48v, but why are the amps and watts so low on the controller when the panel says 17amps and 730 w.

A second panel in series will increase the volts? Then it could be small? Wouldn't it go above 48v?

 

[DannyG]

Your panel's voltage is too low. A second panel in series should fix your problem.

I see now that it says best DC voltage 60 - 90v. Does that mean the 48 v pump actually wants 90?

 

[DIYrich]

I see now that it says best DC voltage 60 - 90v. Does that mean the 48 v pump actually wants 90?

Anything over 60v should work. Don't go above 90v.

 

[OzSolar]

What about your pump supplier? They should be helping you.

Regardless, some of it's spelled out right there on your controller.

It looks like you've got all sorts of things going on.

Voltage is too low. A 2nd identical panel is series will get you right on the edge of too high but should be fine unless it get cold there. But the amps will exceed the controllers rating by a little bit so that may be a problem. This is why it's better to use smaller panels with a lower Voc for solar water pumps. You can add panels in much more manageable increments to get to the ideal power requirements

The next one I see is that's a suction pump limited to 8M of suction. Elbows and other fittings and too small of a suction line will reduce that 8M drastically. Those type of pumps are very sensitive when they operated anywhere near thier max suction rating. And then they must be seeing the ideal voltage and amperage then.

And that suction lines usually needs to be primed and quite susceptible to losing thier prime.

You've got to test this set up before you try to deploy it. Set the pump up next to a tank with with a 2M or less of pipe on both output and suction lines. Have it feed right back into the same tank. By testing in this controlled environment you can prove what it does before you start adding other variables.

 

[littleharbor2]

I see now that it says best DC voltage 60 - 90v. Does that mean the 48 v pump actually wants 90?

Previous replies have answered a number of those questions, but I will add the open circuit voltage is close to the limit of your MPPT controller but the voltage drop on that long run I think you'd be safe unless it gets really cold where you live. Yes, Pump controller is a MPPT. It wants higher voltage and it does the down conversion to the correct voltage, but you always have to be higher. If you have less voltage than it than it wants, it just doesn't work

 

[DannyG]

Thanks everyone. I still don't understand why the watts and amps are so low. The controller reports the max 41 v but so low on watts and amps.

Does it need to be an identical second panel? First, it's kind of expensive and second it's rather large. Should I try to sell this panel for a new setup?

I also do not understand how shortening from 90m to 15m didn't change much.

I'm probably about 4m above the river. It will pump water but not to the desired height.

 

[DannyG]

Thank you for your feedback.
At this point I am feeling rather frustrated. Obviously, I did what I planned, haha, but I didn't have a very good plan. I bought the controller and pump as one unit and the solar panel separate. I live in remote Thailand and ordered online. The pump store had recommended 2 x 330 w panels, but I also was told that the watts should be 1.5 times bigger than the pump, so I didn't know what to do and bought a bigger panel.
I'm sorry for my ignorance around the electrical workings, but what I don't understand is why the controller can show the maximum 41 volts but can't also max out the amps and watts? And how did shortening that much wire not make a difference? Why would the mppt light flash when the panel was farther away but not when theoretically I greatly increased the power by shortening the wire so much(I think I'm extra frustrated because I spent a lot of energy to reduce the wire length and it barely did anything)?
Is there no way this can work as is? If not, what would be the cheapest solution? The panel was more expensive than the pump/controller combo. Adding a second one also puts me too close to the maximum levels of the controller as someone pointed out. Can I add a second random solar panel that I can find cheap or free?
I thought this was going to be easy. Just two things to buy. Somehow I missed the mark

As suggested, I think I should set up a control situation and see what happens.

 

[LanduytG]

My panel 48v 730w mono is about 100m away from my controller/pump 550w dc. The controller has a mppt. I am using 4mm solar cable. I am then using 1 inch pipe trying to run the water about 6 meters up over a 100 meter distance. In midday sun, I am able to pump water, but not when I attach the outtake pipe. It seems to just run but not actually push any water out. The controller is saying it's at about 1950 rpm, 38v , 4 amp and 150 to 170 w.

What's the biggest issue? The panel to controller distance? I can maybe shorten it to 85 or 90 meter

How can I test the solar panel to see what

First you need to look at the pump spec and see how much head it will push. Doesn't matter how much power you have if the pumps not capable of pumping 18ft of head. 18ft of head is about 8psi of pressure. Takes a good pump to over come that. Until you look at pump specs everything else is moot.

 

[OzSolar]

Should I try to sell this panel for a new setup?

Yes

Below is an example I found. See how they are using smaller panels in series?

centrifugal surface pump with solar power DC 72V domestic solar pump | DC SURFACE SOLAR PUMP | DIFFUL

centrifugal surface pump with solar power DC 72V domestic solar pump from Brand:DIFFUL;Model:DCPM;Type:surface solar centrifugal pump; Material:Stainless steel; Application:domestic water supply,irrigation; Voltage:DC 72V; Package type:wooden case;

www.diffulpump.com

 

[OzSolar]

Until you educate yourself on how all this works you're going to struggle.

 

[LanduytG]

Yes you need to know what your pump is capable of. Forget about electric side until you know that. If your pushing 18ft vertical head you need and pump that will do that. Then you will know what you need on the electrical side. I feel you don't have a good understanding of what your doing. Until you do your just guessing.

 

[DannyG]

Yes

Below is an example I found. See how they are using smaller panels in series?

centrifugal surface pump with solar power DC 72V domestic solar pump | DC SURFACE SOLAR PUMP | DIFFUL

centrifugal surface pump with solar power DC 72V domestic solar pump from Brand:DIFFUL;Model:DCPM;Type:surface solar centrifugal pump; Material:Stainless steel; Application:domestic water supply,irrigation; Voltage:DC 72V; Package type:wooden case;

www.diffulpump.com

View attachment 275337

Yes, but the manual also says that the panels should be 1.5 times bigger. This adds up to 600 only. That's what confused me

 

[OzSolar]

Yes, but the manual also says that the panels should be 1.5 times bigger. This adds up to 600 only. That's what confused me

At some point you're going to have to take charge of your own destiny.

 

[DannyG]

At some point you're going to have to take charge of your own destiny.

What's that mean in terms of making sense of the choice of panels. I tried to take charge of my destiny and chose the wrong panel. Now I am asking for feedback from a group that is supposed to have specialty knowledge and trying to not just make my own choice without understanding.