Irrigation well pressure problems

[skyboss]

Question for the well guys. I bought a property last year and have an old 4" well that I have paired with a Cycle Stop Valve that I use exclusively lawn irrigation and a couple of yard hydrants. The current pump is 1/2hp of unknown age and appears to be set at roughly 50ft. Static water level seems to be around 35ft. The well is roughly 40yrs old and I have no idea if or when the current pump was replaced. When running the irrigation the pump runs wide open and builds about 44psi and all the irrigation zones are around 9 gpm. I use the CSV so I can water the landscaping with the yard hydrants and it maintains 50 psi while using impact sprinklers and hose end spray guns. The well is piped directly to the irrigation main water line and the CSV and pressure tank are right next to the well.

I ran into a problem last night while watering my landscaping with a hose end yard sprinkler. It was running fine and holding 50psi. I came back and saw the well pressure dropped to 20psi. I turned off the hydrant and the pressure wouldn't build to cut off the pressure switch. I turned off power to the well and waited about 20 minutes. I turned it back on and it built pressure but when I tested a sprinkler zone it dropped back down to 20psi and wouldn't run the zone.

This morning I tried it again and it ran all the zones normally and maintained pressure and flow. Any guesses to what caused this? Would it be worth having the pump pulled and inspected or just wait and see if it happens again?

 

[Valveman]

Sounds like yo maybe pumping the well dry. Use a clip around AC amp meter to verify. 1/2 HP pulls 5 amps when pumping a lot of water like at 44 PSI. But if it drops to say 2.5 amps when the pressure drops, it is pumping air. With the CSV you can adjust your sprinkler zones to a smaller amount to prevent pumping the well dry. The CSV will let you cut the sprinkler zones in half and still not cycle the pump, as you will have to run them twice as long to get across.

A Cycle Sensor to protect the pump from dry running maybe something you need.

 

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[skyboss]

Thanks for the reply. It's my first time owning a well so I've had a learning curve getting everything set up and one of your employees was really helpful when I was getting the original system set up.

I'll see if I can duplicate the problem with an amp meter on it. It's been a really dry and hot finish to summer in eastern Nebraska and I imagine that could be one of the reasons it hasn't happened until now. I'll probably put a longer recovery time between zones as well.

I'm don't have much data on the well and couldn't get a weighted tape measure past the pump due the the 4" diameter but from what I could tell on the pump curves even if I could drop the pump deeper I'd need a larger pump to make up for the increased head requirements.

I'll take a look at the Cycle Sensor. Looks like a good way to take the pump offline if it happens again.

 

[Reach4]

Setting the pump deeper does not require a stronger pump. It is the distance from the surface of the water to the pressure switch that determines how much pressure a pump must put out.

Yes, if the water level decreases, then you might want a stronger pump. A 7 gpm 1/2 hp pump will lift water from lower than a 10 gpm pump will. Maybe you could put smaller nozzles on your impact sprinkler heads. https://www.rainbird.com/sites/defa...l-products-catalog_impact_sprinklers_only.pdf is one thing that talks about nozzles.