How to Recover a Lost Submersible Well Pump

[bdhsfz6]

I'd guess they drill the well deeper than the water level for a few reasons.

1. The water table may fluctuate seasonally or with rain.
2. The bore may not refill as fast as you pump it out, depending on the ground conditions.
3. The well refills from the bottom few feet of the point where it's perforated, not anywhere along the rest of the length of the bore. So the deeper they go through the aquifer the more pressure is available to force water through the screen at the bottom, the faster the bore will refill as it's pumped out.
4. They charge by the foot!

A couple of other possible reasons?

5. The deeper the pump is set, the more HP is required to get the water to the surface.
6. Extra room for sediment to accumulate.

 

[3Ts]

5. The deeper the pump is set, the more HP is required to get the water to the surface.

I was under the impression that it was the distance from the top of the water column to the surface that determined the HP of the pump. (.43 psi per foot) The distance from the top of the water column to the pump didn't matter for HP calculations because there would be more (or less) pressure at the intake of the pump. The water column above the pump determined how much water could be drawn out before the pump had to stop and let the well refill. ('course if the refill rate is more than the pump rate, one could run the pump continously).

 

[stumblinhorse]

A couple of other possible reasons?

5. The deeper the pump is set, the more HP is required to get the water to the surface.
6. Extra room for sediment to accumulate.

Extra HP is cheap compared to digging the hole. My guess is they didn’t bring enough pipe. No good reason to be more than about 40-50 feet from the bottom originally. If the well collapsed some you take a section out or 2. But I wouldn’t start that way on purpose.

 

[MossRoad]

A couple of other possible reasons?

5. The deeper the pump is set, the more HP is required to get the water to the surface.
6. Extra room for sediment to accumulate.

I'd agree with #5 to a point. If the well can recharge at the same rate or faster than the pump can pump, it shouldn't make a difference until you get past the water level in the ground. The extra HP would only make a difference to get the water past the point of the water level to the surface, wouldn't it?

So maybe the deeper the surface of the aquifer, the more HP would be required to lift it to the top of the well casing.

I'm sure there's something I'm missing there.

 

[MossRoad]

I was under the impression that it was the distance from the top of the water column to the surface that determined the HP of the pump. (.43 psi per foot) The distance from the top of the water column to the pump didn't matter for HP calculations because there would be more (or less) pressure at the intake of the pump. The water column above the pump determined how much water could be drawn out before the pump had to stop and let the well refill. ('course if the refill rate is more than the pump rate, one could run the pump continously).

Like he said a few hours ago!

I really should read all the responses before I post.

 

[LouNY]

If you delve deep into the specs on quality submersible pumps you can find quite a bit of interesting information.
There are rated for the lift from the standing surface of the water while in use. The amp ratings are at the nominal
lift and gpm specified. If the pump has a lower head requirement it may need to be throttled back some place in the system.
For example a pump rated for 13 gpm with a lift of 150' will pump much more then 13 gpm if it only has a 20' lift, in doing so
the amperage may well be higher then the motors rating, pinching down the flow to the design gpm will usually get the amp load back into the spec.
For the same gpm as the lift requirement increases so does the pump cost and motor amperage and the number of stages on the pump.

Edited changed 20" to 20'

 

[newbury]

<snip>
For example a pump rated for 13 gpm with a lift of 150' will pump much more then 13 gpm if it only has a 20" lift, in doing so
<snip>

Did you mean 20' (feet)?

 

[LouNY]

Yes, of course 20" would require even more throttling

 

[JasperFrank]

I use to just rough it till I got it fixed, cause I just hate contractors..........
Then, I got married....

 

[Egon]

Pump:
number of stages determine pressure
diameter of stage determines volume
amp draw or HP is dependent flow rate and distance from the standing water table and final elevation at delivery point.
restricting flow can be done by closing discharge valve, drilling a hole in some pump stages, bypass line to well bore. Or altering the number and stages of the pump.
valveman makes a valve that bypasses to meet a predetermined flow rate.