solar only water pump set up

[oldsubsailor]

I am trying to set up a off grid, no battery well pump for irrigation around the house. Well is 200 ft deep, static water level 40ft. Pump is place at 100 ft. I have a 4 panel array that I have built using Harbor freight panels ThunderBolt 100 watt, 18vdc, 5.56 amps. I have them wired 2S,2P. I am getting 36VOC out of the set up. I bought a pump and controller off ebay. Controller max input is 30V. I am tripping the controller every time the sun gets a little bright. I know that I need to reduce the voltage from the panels. I thought I could just use a step down voltage regulator thinking I could use that only to find out that the regulator will not work on solar or wind generators, I do not understand why this is but it does not work on solar. My question is......how can reduce the output voltage on the panels, or can I obtain a Mppt that will handle the 36 volts and then just take the output off of the Mppt and supply the power to the existing pump controller? There is possibly a very easy solution but trying to set this system up is making me doubt anything that I thought I knew about electricity. Please help

 

[AntronX]

Try to wire panels in 1s4p config.

 

[oldsubsailor]

I thought that would only give me 18 volts to a 24 volt pump. But I will give it a shot and see what happens. And thanks for the input.

 

[OzSolar]

What sort of controller did you buy off of eBay? A battery charging one or one specifically for a solar pump?

 

[oldsubsailor]

yes it is specifically for this pump. It all came as a package, pump, controller, and various items such as tape, pipe connections..etc. It did not come with a manual of any use. The manual that comes with the Chinese pumps is not correct...terminals not labeled correctly, error codes wrong. What you get when you go on the cheap.

 

[OzSolar]

Oh, I totally get your pain about the Chinese pumps, I’ve done a lot of them. To be honest, I’ve had fantastic success with them.

If it was me, I would start with the pump and a 5 gallon bucket and just one panel and see what happens. (Hook up the hose to the pump so it returns to the 5 gallon bucket.)

Most of those pumps are positive displacement so so they still pump water when they’re getting even just a few watts.

 

[oldsubsailor]

OzSolar, you say you have done a lot of these Chinese pumps. Do you have any literature at all on them. Directions on how to set certain parameters and things like that. I hooked up my 4 18 volt, 100 w panels in par, gave me 18 volts and around 300 watts. Controller showing codes 70lp 50lp 68lp. at random as soon as controller is turned on. I am this point thinking about going back to 2s2p. That gives me the 36 volt that I could then obtain a 24 volt MPPT that can handle the 36 volts and drive the pump controller with that. Have you ever tried that and if you did, did it work?

 

[anasgarba0]

Pls i need power dc water pump that rated below
Voc 96v
Hp 1.2hp
Power 900w

Panel specifications
Voc 56v
P0wer 210w

Pls help how many panel do need to this pump