Why set a pump at 520'

[stevenshager]

The issue is that an unrestricted spigot is flowing 2 gpm. Two years ago it would have flowed close to 4 or 5 gpm.

A Grundfos 5S10-22 is hanging on 1" Schedule 80 PVC at 520'. The static level is presumably around 180'. Cased with 4.5" PVC from 40' down to 790' total depth. 20 years ago, when well was completed, the TEST DATA sheet read: STATIC LVL 180', TIME 30 MINUTES, RATE (GPM) 7, PUMPING LVL 195'

I plan to pull the pump. I expect to find a crack in the pipe, since this pump is rated for around 4 GPM at that depth, and I am only getting 2 GPM.

I would prefer better household pressure. I would like to have a 50/70 at the pressure tank. So when I reset the pump I'm thinking about removing 8 sticks from the string, and reducing my pump depth to 352', rather than the 520' it's set at now.

SO, I'm wondering, why would they have set the pump so darn deep?

 

[Valveman]

It doesn't matter how deep the pump is set, it will still only be lifting from the actual water level. A 5S10-22 can still pump 4 GPM from 400' at 40 PSI. If the static is really at 180', that pump should make 7 GPM with a wide open faucet until the water level starts to drop. If it doesn't start out at 7 GPM, the water level is deeper than you think or something is wrong with the pump or pipe.

The reason for setting the pump at 520' with a static of 180' is that is like having 450 gallons stored in a cistern to be able to use as much flow as needed for short periods of time. Otherwise a 2 GPM well would not be able to supply a 3 GPM shower.

Check the amps. 9 amps means you have a hole in the pipe. Low amps would mean the pump is worn, clogged, or the water is deeper than you think.

 

[Sponsor]

 

[Fitter30]

520-180=340 x 1.47 gallons per ft= 500 gallons
Probably not enough volume and slow recovery.

 

[Valveman]

You could set the pump more shallow and use a smaller pump if you stored water in a cistern. A well that only makes 1 GPM can supply 1440 gallons a day and feed 5 houses that way. A smaller pump, set at 300', and delivering 1-3 GPM to a cistern is an option to pumping from so deep.

 

[stevenshager]

It doesn't matter how deep the pump is set, it will still only be lifting from the actual water level. A 5S10-22 can still pump 4 GPM from 400' at 40 PSI. If the static is really at 180', that pump should make 7 GPM with a wide open faucet until the water level starts to drop. If it doesn't start out at 7 GPM, the water level is deeper than you think or something is wrong with the pump or pipe.

The reason for setting the pump at 520' with a static of 180' is that is like having 450 gallons stored in a cistern to be able to use as much flow as needed for short periods of time. Otherwise a 2 GPM well would not be able to supply a 3 GPM shower.

Check the amps. 9 amps means you have a hole in the pipe. Low amps would mean the pump is worn, clogged, or the water is deeper than you think.

Thanks @Valveman . I'm relatively sure that it is pulling the 9.8 amps. Since that is the load shown in the specs I thought the pump was "okay", and it might still be. I'm gleaning from these replies however that a pump will not pull maximum amps unless it is working really hard. I'm going back up there tonight so will be testing again tomorrow to verify the amps. Crossing my fingers that I can drop a weight and bobber to 180' or more without getting caught on the downhole pipe or wire to verify depth. Probably going to have to pull with a HF electric hoist and scaffolding.

Very seriously considering your CSV. Is that best placed just below the pitless? If I do have any check valves in the downhole string (other than one that might be built into the pump), those would have to come out or the CSV would have to go under them? Does the CSV also act as a check valve?

 

[Fitter30]

Bypass the pressure switch with all valve closed in the house measure the pump pressure only takes a few seconds. Knowing the depth the factory can tell u the shut off pressure. Call there tech line.

 

[stevenshager]

Bypass the pressure switch with all valve closed in the house measure the pump pressure only takes a few seconds. Knowing the depth the factory can tell u the shut off pressure. Call there tech line.

I do not think this is a water level issue as we have been gone from the house for 2 weeks. I tried dropping a string but it stops at about 150' , so no chance to see if water is at 180'. @Valveman said it could still pump 4 GPM from 400' at 40 PSI.

I don't have a great way of bypassing the pressure tank, so it is still in the loop (I'm positive that the tank is not an issue).

I closed the valve to the house and held the pressure switch down to make contact. Looks like 43 PSI is about all it will push. Call me crazy but at the wellhead, on one side I'm pulling 9.7 amps and on the other leg 8.44 amps. I thought both legs on 240 were supposed to pull the same value? It's running #8 200' from house to wellhead, and #8 520' from wellhead to pump.
.

Waiting on some pipe elevators to arrive on Tuesday so I can pull it.

 

[Reach4]

CSV does not act as a check valve.

You only want a check valve in and/or right above the pump. If you have an above ground check valve, that is important to know for understanding your symptoms. If you have no extra check valve, then the fact that you hold pressure means you don't have a hole in the pipe. An extra check valve can hold pressure, even if there is a hole upstream of the check valve.

Wires should pull identical amps. Try putting the ammeter around both hots. Ideally the meter will show 0 amps, but fields do not always exactly cancel. But if you end up seeing 1+ amp net, that would be compatible with a big electrical leak to ground. I think it more likely that the meter is getting different coupling depending on the angle of the wire thru the clamp.

 

[Fitter30]

Both wires should be the same amps. Check voltage while running between the wires and to ground

 

[Valveman]

By closing off the valve to the house and pressure only getting up to 43 PSI is max pressure without having to bypass the switch. That pump can only build 43 PSI if it is lifting from 520' deep. BUT, at zero flow or max pressure it would be drawing about half of that 9.7 amps. Full load at 9.7 amps tells me the pump is producing 5-6 GPM. I think there is a hole in the drop pipe or the side of the pump. Those long Grundfos pumps can have a strap come loose and make water squirt out between the last couple of stages on the pump. This is below the check valve so water doesn't leak back when the pump is off.

If the water level was at say 200' or so, would have to bypass the pressure switch to test the pressure as it should go up to 177 PSI. I don't think your water level has dropped all the way to 520'. I think it is at 180' or so as it should be and the water is just not getting pumped up the pipe to the surface.