What size submersible well pump & motor do I need?

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3nails4u

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Greetings, I am in need of a new well pump and would like to understand what I should use. Original set-up has quit running (motor was stuck) and activating the overload protection. Pulled it myself and needed quite some force to turn the motor shaft. Once free it would start and run on it's own but I was not about to lower it back in the hole. I did not locate my house where original owner of the property placed the well and prepared a house sight. So the pump installed was not calculated for my needs. Pump was a Grundfos 16S15-14, 16 gpm, 284 ft. motor was Franklin 1.5 hp. 3 wire 1 ph. Well was tested at 55 gpm at time of install in 1992. Pump sits at @ 87 ft. and water in well case is as high as 3 ft. below surface and as low as perhaps 40 ft. from surface depending on time of year. Pump to pitless adapter is 1 1/4" schedule 120 for first 10 ft. from pump then schedule 80 to the exit. No idea why the change in strength for that short distance. A T-fitting outside the case with a pressure reducer provides water usage at the well sight (built a cabin at the original house sight. A 1.5" poly pipe from the T takes the water up the road to our house. Buried @ 5 ft. deep.

We decided to build further up the property so as to have sunlight 365. From the well to the house, the road is about 2400 ft. with each pipe to pipe connection I added a swing check valve and a spring type check valve at the T by the well. The elevation from top of well to house is @ 200 ft. The water is pumped into a tank with a float switch shut off. A contactor allows the well to be operated at either location. Pressure is not a concern, volume however is. I would like for the pump to be able to keep up with the water usage and not allow the tank to empty while running lawn sprinklers etc... at the house. I would like to have 15-20 gpm to the tank. We live out off the beaten path but do have PUD power but not 3 ph.

Hopefully this is all one needs to figure out the size I would need. If not, please ask. Naturally I am anxious to get water again, so thank you to anyone that can provide me with some info.
 

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That pump was way oversized for a well that is only 87' deep and a static of 3'. But it will be perfect for an additional 200' of lift as you need now. Motor sticking like that is usually from all the debris in the motor that is caused when the pump is cycled on and off too much. You really shouldn't need a storage tank and extra boost pump. Just set the pressure high enough to get 40/60 up at the house and use the pressure reducer at the bottom like you are now.

If you put the pressure tank at the house the setting would be 40/60. But if you put the pressure tank and switch at the well the setting would need to be 120/140 to get 40/60 up at the house. You would then need the 2HP 16S20 pump to make that much pressure, but then you would not need a second pump.
 

3nails4u

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Thank you so much for taking the time to reply.

The length of the pipe up to the house and the extra check valves, 5, if my memory works, had me questioning what amount of friction my set-up would be fighting. I will consider the pressure tank route but we like the hundreds of gallons of water hanging around in case of a power outage or pump problem. If I might ask another question. Would a replacement pump the size I had be able to run another 300-400 ft. pipe length and 150 ft. in rise? I would then move my tank up higher and use gravity if the power failed and use a 40/60 pressure tank in the house as you suggested.

Again, thanks so very much for your time and help.

Kind regards,

Rik
 

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The 16S15-14 pump you have can pump from 420' which is the same as 181 PSI. It will make plenty of pressure to make up for a little friction loss and the extra 150' of lift. However, that pump has an excellent built in check valve, and it is the only check valve you want in the entire system. An extra check valve at the surface or in the elevation will cause water hammer from the faucets to the bottom of the motor in the well.

Most people don't notice the well has quit until the storage tank is empty anyway. Water in a storage tank requires and extra boost pump and controls as well as the need to treat the water sitting in storage. All you need to do to make your well pump last a life time is to prevent it from cycling on and off too much. A Cycle Stop Valve can do that for you. This allows the use of only the one pump and no extra tank and controls. The water coming from the well will always be fresh and not need treatment like water sitting in a vented and exposed storage tank.

Installing a pressure tank at the well head it would need the pressure switch to be set at 100/120 to give you 40/60 up at the houses. Using a CSV1A Cycle Stop valve set at 110 PSI at the well head would give you a strong constant 50 PSI up at the house. Even with a CSV I would use a 60 to 86 gallon size tank on this system as you need a larger tank at 100/120 pressure than at 40/60.

Another option is to install the CSV1A at the well head and use a 20 gallon size tank with the pressure switch up at the house as it will only need to work with a 40/60 pressure switch. However, with this set up the power for the pump would need to come from the house where the pressure tank is located. If the power for the pump is at the bottom of the hill the larger tank and 100/120 setting would work from down there.

If you really want a cistern storage tank I can help you with that as well. But if you keep the well pump from cycling and have a generator handy for power outages you won't need or have all the hassles of a cistern storage tank. I set up lots of cistern systems but I only do that when absolutely necessary, like for a low producing well.
 

3nails4u

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The 16S15-14 pump you have can pump from 420' which is the same as 181 PSI. It will make plenty of pressure to make up for a little friction loss and the extra 150' of lift. However, that pump has an excellent built in check valve, and it is the only check valve you want in the entire system. An extra check valve at the surface or in the elevation will cause water hammer from the faucets to the bottom of the motor in the well.

Most people don't notice the well has quit until the storage tank is empty anyway. Water in a storage tank requires and extra boost pump and controls as well as the need to treat the water sitting in storage. All you need to do to make your well pump last a life time is to prevent it from cycling on and off too much. A Cycle Stop Valve can do that for you. This allows the use of only the one pump and no extra tank and controls. The water coming from the well will always be fresh and not need treatment like water sitting in a vented and exposed storage tank.

Installing a pressure tank at the well head it would need the pressure switch to be set at 100/120 to give you 40/60 up at the houses. Using a CSV1A Cycle Stop valve set at 110 PSI at the well head would give you a strong constant 50 PSI up at the house. Even with a CSV I would use a 60 to 86 gallon size tank on this system as you need a larger tank at 100/120 pressure than at 40/60.

Another option is to install the CSV1A at the well head and use a 20 gallon size tank with the pressure switch up at the house as it will only need to work with a 40/60 pressure switch. However, with this set up the power for the pump would need to come from the house where the pressure tank is located. If the power for the pump is at the bottom of the hill the larger tank and 100/120 setting would work from down there.

If you really want a cistern storage tank I can help you with that as well. But if you keep the well pump from cycling and have a generator handy for power outages you won't need or have all the hassles of a cistern storage tank. I set up lots of cistern systems but I only do that when absolutely necessary, like for a low producing well.
Thank you for the information and your time. The check valves ( swing) have been in place since 07 and all had been great until now. The removal of them would be difficult because of not knowing exactly where they are and at 4-6 ft. deep it would not be fun. : ) I will look into if the spring check valve was installed just outside the casing and remove it. The pump of course had one built into the top. I thought I was helping the water from wanting to head back down the road if one or more gave out. The installation manuals seem to like an extra CV or two, just to cover their bottoms!

I will look for another set=up like I removed and do some serious contemplation about the storage tank. We have been operating with one since 03 when I would haul water up to the house with a trailer until I ditch-witched the pipe in place in 07. Is a replacement Grundfos something you would recommend or do you prefer another company?
 
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