Inrush Question: Shallow well jet vs deep well submersible pumps

[RGS]

I've been getting water from a spring via a brook for years with a 1/2 HP shallow well jet pump. Now having to drill a well and switch to a 1/2 deep well jet pump. Depth will probably be about 140'. I'm wondering if there will be much difference between the shallow well and the deep well pumps as I have a Yamaha 3000w inverter generator and wondering if it will be able to handle the load. I believe the pump that's coming is a Grundfos SQ series but not sure yet if it's 120v version yet.

 

[LLigetfa]

Why not consider a submersible? They are much more efficient and they soft start due to the long wire.

 

[Sponsor]

 

[Reach4]

Your SQ pump is not a jet pump. It is submersible, which is good.

Expect the SQ pump to be more generator-friendly than a jet pump.


Despite the SQ having a slow start feature, I think it is still going to get going faster than a jet pump. Usually with a submersible, you set the air precharge to 2 psi below the cut-in pressure. Should that maybe lowered a tad for an SQ pump? If your pressure switch does not have a lever, then the symptom of your air precharge being a bit high would be a hesitation/stutter when the switch kicks on -- not a big deal.

Incidentally, if your well is 4 inch or bigger, I would consider adding a flow inducer sleeve to the pump. If you want more info, say so. The SQ pumps are 2.9 inch OD.

The SQ pump is going to be a better choice than the more expensive SQE pump.

If you want a 120 volt pump, tell your well driller ASAP.

 

[Fitter30]

Looked at 120vac sq pump 2 wire 12 amps running. Grundfos SQ in their manual they recommend a generator 1.5 times running amps. 3k generator good for
3000 / (120 × 0.8 load power factor) = 31.25 A. First page after cover.

https://s3.amazonaws.com/pumpproducts/pdf/551692_2_Grundfos+SQ+Series+Specifications.pdf

 

[RGS]

Your SQ pump is not a jet pump. It is submersible, which is good.

Expect the SQ pump to be more generator-friendly than a jet pump.


Despite the SQ having a slow start feature, I think it is still going to get going faster than a jet pump. Usually with a submersible, you set the air precharge to 2 psi below the cut-in pressure. Should that maybe lowered a tad for an SQ pump? If your pressure switch does not have a lever, then the symptom of your air precharge being a bit high would be a hesitation/stutter when the switch kicks on -- not a big deal.

Incidentally, if your well is 4 inch or bigger, I would consider adding a flow inducer sleeve to the pump. If you want more info, say so. The SQ pumps are 2.9 inch OD.

The SQ pump is going to be a better choice than the more expensive SQE pump.

If you want a 120 volt pump, tell your well driller ASAP.

Thanks very much, Reach4. Very helpful. Re the well width, the quote says they will use 6" casing.

 

[RGS]

Looked at 120vac sq pump 2 wire 12 amps running. Grundfos SQ in their manual they recommend a generator 1.5 times running amps. 3k generator good for
3000 / (120 × 0.8 load power factor) = 31.25 A. First page after cover.

https://s3.amazonaws.com/pumpproducts/pdf/551692_2_Grundfos+SQ+Series+Specifications.pdf

Thanks very much, Fitter30. And also for the link. Looks like the Yamaha will do the job.

 

[Valveman]

There really is no delay in water supply from a jet pump starting, as long as it maintains prime. But the submersible SQ takes a full 5 seconds to get up to speed. Depending on the size of tank you may need 10 PSI less air charge in the tank than the start pressure of the pump. I also think the SQ motor has some way of circulating the fluid inside it, which lessens the need for a flow inducer. But I am not certain of this and a flow inducer never hurts.

 

[RGS]

There really is no delay in water supply from a jet pump starting, as long as it maintains prime. But the submersible SQ takes a full 5 seconds to get up to speed. Depending on the size of tank you may need 10 PSI less air charge in the tank than the start pressure of the pump. I also think the SQ motor has some way of circulating the fluid inside it, which lessens the need for a flow inducer. But I am not certain of this and a flow inducer never hurts.

View attachment 98053

Thanks Valveman. Very interesting.

 

[Reach4]

for 3 inch for SQ pump
3-inch pvc solid sched 40 would work, but is thicker than needed.

ASTM 2949 appears to be 3.25 OD, and Fernco seems to call it thinwall.

https://www.napcopipe.com/sites/default/files/media/PL-PS-005-US-EN-0119.2_D2949.pdf

pvc solid sched 30 od:3.25 ID: 3.00 min wall 0.125 ("thin wall")
D2729 Charlotte part PVC 30030 od:3.25 min wall 0.070

3"x10' Thin Wall PVC DWV Sch 30

PVC Schedule 30 Thin-Wall Pipe is for drain, waste and vent purposes only. It is used in gravity fed waste elimination systems. It is for Non-Pressure systems where temperatures will not exceed 140 degrees F. PVC Schedule 30 Thin-Wall is lightweight, non-toxic. There is no rusting or corroding...

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Charlotte Pipe PVC Sewer Main 3 in. D X 10 ft. L Bell 0 psi - Ace Hardware

PVC 2729 Sewer Pipe is for sewer and storm drainage applications only. It is used in gravity fed waste elimination systems. PVC 2729 Sewer Pipe is highly resistant to chemicals commonly found in sewage and industrial waste and has a smooth internal surface for minimum flow resistance. It is...

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