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DC pump issues

Afaircloth

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Sep 10, 2020
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I have a 12v 400w solar system with a 40A charge controller. The only load I have is a 12V 10A 3.2 gpm deep well pump that lives in a 60 gal barrel (actually three plumbed together) which is temp storage for my rain water catchment system. I have a sump switch for emerg shutoff, and two inverted sump switches for level switches. These are located in a cold water barrel and hot water barrel on a tower for my gravity fed service. The highest point the pump has to lift water is not over 25 feet though it is rated to 230’. When energized, the pump pushes water and the tanks fill, but slowly - maybe a gal/min or less. I checked voltage, and it drops at start up but soon bounces back to over 13V. I have not checked amperage.
Can anyone tell me if this is normal, it seems to me that water should shoot out of the pump. I need to know if its the power, or a problem with the pump.
 

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The temporary dip isn't unexpected. I would speculate it is the initial 10A hit with the charge controller playing a little catch up to float the battery again.

A pump's rating is for 0 head, i.e., you'll get 3.2gpm pumping along the ground.

Given that it's submerged, and you're pumping up 25', I would expect a 20% loss or so - around 2.5gpm.

You also have friction losses in your piping. The length of pipe and the diameter can have a big influence.

Can you summarize the total change in height the water is pumped as well as the total distance the water moves (including the height change) and the diameter of the pipe?
 
I looked and I can't find a datasheet for the flow at different "head" (lift) distances. But as the head increases the flow decreases. The pump rating says 3.2GPM but doesn't say at what head. So if you pump right out of the pump (no head) into a bucket and the flow is less than 3 gallons a minute, then for sure is wrong.

The amps running would be good to know. There is a vent in the barrel so it doesn't create a vacuum, right?
 
I looked and I can't find a datasheet for the flow at different "head" (lift) distances. But as the head increases the flow decreases. The pump rating says 3.2GPM but doesn't say at what head. So if you pump right out of the pump (no head) into a bucket and the flow is less than 3 gallons a minute, then for sure is wrong.

The amps running would be good to know. There is a vent in the barrel so it doesn't create a vacuum, right?

That's a good process for testing the pump.
 
The temporary dip isn't unexpected. I would speculate it is the initial 10A hit with the charge controller playing a little catch up to float the battery again.

A pump's rating is for 0 head, i.e., you'll get 3.2gpm pumping along the ground.

Given that it's submerged, and you're pumping up 25', I would expect a 20% loss or so - around 2.5gpm.

You also have friction losses in your piping. The length of pipe and the diameter can have a big influence.

Can you summarize the total change in height the water is pumped as well as the total distance the water moves (including the height change) and the diameter of the pipe?

I disconnected the union at the top of the barrel so travel is roughly 50 - 60 inches (a few inches above a 60 gal olive barrel). 1” pipe. I will measure amperage this weekend
 
The temporary dip isn't unexpected. I would speculate it is the initial 10A hit with the charge controller playing a little catch up to float the battery again.

A pump's rating is for 0 head, i.e., you'll get 3.2gpm pumping along the ground.

Given that it's submerged, and you're pumping up 25', I would expect a 20% loss or so - around 2.5gpm.

You also have friction losses in your piping. The length of pipe and the diameter can have a big influence.

Can you summarize the total change in height the water is pumped as well as the total distance the water moves (including the height change) and the diameter of the pipe?
wow @ bolded, didnt know that, am about pulling the trigger on this pump, expected borehole depth is 110ft, to pump into an overhead storage tank 40ft above the ground, anyway of calculating the expected water delivery ?
flow rate is 8gpm and design head is 230ft. would i get upto 5gpm based on the info i posted above?

 
I wouldn't buy that. I would stick with a quality brand NOT sold on ebay.

You have 150ft of head to overcome. Decay is not linear, and a quality pump will give you charts showing flow for given depth/head.

I would expect that you'll get less than 3gpm.
 
I have a 12v 400w solar system with a 40A charge controller. The only load I have is a 12V 10A 3.2 gpm deep well pump that lives in a 60 gal barrel (actually three plumbed together) which is temp storage for my rain water catchment system. I have a sump switch for emerg shutoff, and two inverted sump switches for level switches. These are located in a cold water barrel and hot water barrel on a tower for my gravity fed service. The highest point the pump has to lift water is not over 25 feet though it is rated to 230’. When energized, the pump pushes water and the tanks fill, but slowly - maybe a gal/min or less. I checked voltage, and it drops at start up but soon bounces back to over 13V. I have not checked amperage.
Can anyone tell me if this is normal, it seems to me that water should shoot out of the pump. I need to know if its the power, or a problem with the pump.
Be warned. The Max Head lift is misleading. Max Lift that unit can lift is just 25s meter and not 70 meters as advertised. I got the info from customer service email, that it can lift that high (70m) but only for few min or seconds. Bought 3 and all are dead in 2 weeks time.
 
Be warned. The Max Head lift is misleading. Max Lift that unit can lift is just 25s meter and not 70 meters as advertised. I got the info from customer service email, that it can lift that high (70m) but only for few min or seconds. Bought 3 and all are dead in 2 weeks time.
WOW, you mean this eaxct pump??

this isnt good, if so!!!
 
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