Anyone really understand well pump systems?

[N_Jay]

My new garage/shop is on the land I will be building a house, so I am having the well and septic put in and plumbing a bathroom, and kitchenette in the building.
Current plan is to run the pipe to near where the house will be and put in a underground valve box, with a stub for the house (valve shut off and capped), and a valve for the run to the shop.
Power will follow the run since the power will (at least initially) come from the shop.
Shop will get the tank, pressure switch, motor control box (3 wire pump).
I am trying to figure out "Constant Pressure" systems for when the house goes in.
Sees like there are not too expensive constant pressure booster pumps, but they seem dumb in design, running full power into a restriction device in their output.
Then there are variable speed booster pumps which look great but cost a fair amount.
Then there are pressure regulators, such as the (so called) "cycle stop valve" which seems like a decent idea, except the company puts it before the tank and switch and uses a small tank, so it seems to reduce cycling by greatly extending pump run time. (and most of that run time is into high head pressures for low flow rates.

So what is wrong with using a standard tank design (with a decent size tank), setting the pressure switch to 75/55 PSI, and following that with a 50 PSI regulator and small tank?
Head pressure should not exceed 75PSI plus the lift pressure.
Cycle and run times should be decent as the tank is drained and refilled.

Thoughts?

 

[couch67]

I'm not an expert but 75psi seems awfully high for a well pump. Have you sourced a pump yet and checked max ratings? Its been a while since I looked into it, I recall 60 psi was a common max cutoff.

 

[bobkat]

I'm not an expert but 75psi seems awfully high for a well pump. Have you sourced a pump yet and checked max ratings? Its been a while since I looked into it, I recall 60 psi was a common max cutoff.

My relief valve is set at 72 psi at pump

 

[N_Jay]

60 PSI is typical high end in the house, with 80 PSI as a max (from my understanding of code)
Pump is good for 200+ feet which is another 85 PSI.
I an at about 125 feet so I have at least 32 PSI (75 feet) of margin.

So even if the pump is only good for 60 PSI at 200 Feet, I am below that.

 

[larry_g]

I have had both on/off pumps with a large pressure tank and now have a variable speed constant pressure pump. I went with the variable speed at this place because I do a lot of watering in the gardens during the season and during the winter just household duties. When watering gardens the pump will deliver the water to run 3 #35 rainbirds. When running the house the pump will draw only a couple amps to maintain pressure. and that is a great thing when the power is our ant I have to run the pump from the generator. The variable speed pumps have little to no inrush current so a small generator will run them.

I also question your reasoning to run the pump to 75psi only to regulate it back to 50? I had to replace my pressure regulator once and it was at 70psi and ended up blowing out some hoses so I run the system as 55psi and all works good. The other mechanical systems for constant pressure all seem to have downsides to me and I'm very happy with choosing to go with the variable speed pump. The variable speed system I have is basically a variable frequency drive, VFD, that controls the speed of the pump by using a pressure transducer to sense pressure and adjusting the speed of the pump to match maintain set pressure.

lg
no neat sig line

 

[N_Jay]

I have had both on/off pumps with a large pressure tank and now have a variable speed constant pressure pump. I went with the variable speed at this place because I do a lot of watering in the gardens during the season and during the winter just household duties. When watering gardens the pump will deliver the water to run 3 #35 rainbirds. When running the house the pump will draw only a couple amps to maintain pressure. and that is a great thing when the power is our ant I have to run the pump from the generator. The variable speed pumps have little to no inrush current so a small generator will run them.

I also question your reasoning to run the pump to 75psi only to regulate it back to 50? I had to replace my pressure regulator once and it was at 70psi and ended up blowing out some hoses so I run the system as 55psi and all works good. The other mechanical systems for constant pressure all seem to have downsides to me and I'm very happy with choosing to go with the variable speed pump. The variable speed system I have is basically a variable frequency drive, VFD, that controls the speed of the pump by using a pressure transducer to sense pressure and adjusting the speed of the pump to match maintain set pressure.

lg
no neat sig line

Is it a deep well VSD pump, or a booster/jet VSD pump?
Unfortunately I did not think about this ahead of time, so the standard speed 3 wire pump is already in place.
I would guess with some creativity I could use a VSD drive on it, but I am not sure the starter winding is designed to be a full current third phase.
Maybe in 10 or 15 years when it dies, I will go with a proper VSD pump.

 

[mike93lx]

The tank at my last house was precharged to about 45 psi. 7.5gpm pump at 125' down with a standard pressure tank. Never had an issue with flow or pressure.

Unless you have some special requirements, I would keep it simple

I replaced the original pump about 5 years ago. It was put in the hole in 1970. Pumps can last a long time

 

[N_Jay]

Maybe I am picky but every time I stay somewhere on a well, the cycling of the water during showers really bugs me.

 

[larry_g]

Is it a deep well VSD pump, or a booster/jet VSD pump?
Unfortunately I did not think about this ahead of time, so the standard speed 3 wire pump is already in place.
I would guess with some creativity I could use a VSD drive on it, but I am not sure the starter winding is designed to be a full current third phase.
Maybe in 10 or 15 years when it dies, I will go with a proper VSD pump.

Yes it is a submersible pump. In a 220; well set at 180' down. The water in the well comes to ~30 ' from the ground level. That 30' is what you use for a head measurement not the 220 or 180'. The pump is only lifting the water against 30' of head.

Another thing to think about, have a stub out for watering lawns and gardens. On mine I shut off and drain the lines going to the gardens so I don't have to worry about freezing.

lg
no neat sig line

 

[Debcrow]

no neat sig line

 

[mike93lx]

Maybe I am picky but every time I stay somewhere on a well, the cycling of the water during showers really bugs me.

I've never experienced that

 

[Solarphil]

Maybe I am picky but every time I stay somewhere on a well, the cycling of the water during showers really bugs me.

If you’re feeling a drop in flow, that’s because the captive pressure in the tank bladder hasn’t been tuned to the pressure switch setting - a surprisingly common mistake.

Whatever your cut-in pressure on the pressure switch, the pressure in the bladder should be set 2-3 psi lower. That has to be set with no water pressure in the system. In addition the accuracy of the pressure gauge found on most well plumbing systems is only accurate to a ballpark range, as are most folk’s air pressure gauges. To get the best performing system, a good plumber will cycle the system a handful of times, increasing or decreasing the tank bladder pressure and measuring the gallons of output before the pressure switch triggers. When you get it right, you get the most useful gallons out of the tank for the lowest energy consumption, and no drop in flow as the pump kicks on.

I’m not a big fan of the variable speed pumps, not when you can get better performance for a fraction the cost out of a large pressure tank set correctly.

Whatever you do, if the pressure tank and switch are in the shop, then you don’t ever want to have a shutoff between the pump and the pressure switch, so rethink the valving in your underground valve box. Otherwise it’s possible to have the pump run uncontrolled against a dead end; no bueno.

 

[klassenl]

Where I live it seems the complexity and cost of contant pressure pumps pushes me away from them.

We have a shop where we do some work that had a constant pressure system go dry and this ruined the pump. If you have a normal pump/pressure tank system you can go just about anywhere to get a new pump. If you have a pump with a variable speed drive on it there may be only 2 or 3 places that can supply the correct pump.

 

[NakeDiesel]

Here at my place, I started with nothing. First step was setting a meter pole for the electric to hit my property and pay pso 10k to run lines 1/4 mile to my place. On that meter pole I had 400 Amp service brought in. I split it to 2 main disconnects with breakers. One for future house, one for future shop.

Next was drilling water well. I powered it off of a trenched line from the house box on the pole. Built a very insulated well house that contains the pressure tank and an outlet for heat tape.

Put house in and ran 200 Amp rated copper to it from the pole. I used 1" poly pipe from the well to the house with freeze proof hydrants, 1 at well house, 1 at back of the house. With the poly pipe it's easy to cut/branch and added a branch towards where my shop would be eventually, put an inground box with a valve and plug.

Several years later built the shop and ran water line on to it and electric from its own box on the pole to the shop.

 

[theoldwizard1]

Then there are variable speed booster pumps which look great but cost a fair amount.

You hit the nail n the head right there !

About the only way you can make a powerful motor that has variable speed is a 3 phase motor with a variable frequency drive. $$$. Inexpensive, reliable mechanical pumps have been a "quest" for engineers for many, many years.

The only good news is that VFD keep getting cheaper and cheaper. The industry as a whole has not kept up with advances in power electronics over the past 10-20 years.

 

[Jlarson]

We've installed a few poly tanks and also built a few steel storage tanks for residential in the past along with constant pressure boosters, everyone that went that way really loved them. We've done grundfos and franklin systems.

 

[larry_g]

We've installed a few poly tanks and also built a few steel storage tanks for residential in the past along with constant pressure boosters, everyone that went that way really loved them. We've done grundfos and franklin systems.

That is what my son has. He came up with a low flow well so installed a transfer pump in the well and that pumps into a 1500 gallon tank that has a VS pump to deliver to the pressure tank in the house.

lg
no neat sig line

 

[N_Jay]

I was not thinking about the true head pressure having to do with the water height as oppose to the well depth, but even so, if you are concerned with the maximum designed head pressure, a 3/4 HP 10 GPH pump will still work at 200 feet, so the pump can easily generate the pressure I was looking for.

I am not sure how you don't feel a 15 to 20 PSI shift between the peak pressure right around pump shut off and the low right before it kicks back on. Tank size and "fine tuning" the air pressure just spreads out those high and low points.

As for the two shut offs, yes doing something stupid like shutting off the line would be a big no-no, so thinking about it, I will probably skip that valve. (Since there is no reason to stop flow to the shop if that is where the pressure switch lives.) If I have to service that line, I have to shut it all down anyhow.

If I decide to move the switch, it would be after building the house, so I can replumb it at that point.

Yes, Variable speed motors are mostly just three phase run off a VFD, as they have almost completely replaced DC motors with speed sensors or rotation counters.

And yes, I am doing things a bit backwards waiting to get the shell up and having permanent power brought in once.

 

[u3b3rg33k]

My new garage/shop is on the land I will be building a house, so I am having the well and septic put in and plumbing a bathroom, and kitchenette in the building.
Current plan is to run the pipe to near where the house will be and put in a underground valve box, with a stub for the house (valve shut off and capped), and a valve for the run to the shop.
Power will follow the run since the power will (at least initially) come from the shop.
Shop will get the tank, pressure switch, motor control box (3 wire pump).
I am trying to figure out "Constant Pressure" systems for when the house goes in.
Sees like there are not too expensive constant pressure booster pumps, but they seem dumb in design, running full power into a restriction device in their output.
Then there are variable speed booster pumps which look great but cost a fair amount.
Then there are pressure regulators, such as the (so called) "cycle stop valve" which seems like a decent idea, except the company puts it before the tank and switch and uses a small tank, so it seems to reduce cycling by greatly extending pump run time. (and most of that run time is into high head pressures for low flow rates.

So what is wrong with using a standard tank design (with a decent size tank), setting the pressure switch to 75/55 PSI, and following that with a 50 PSI regulator and small tank?
Head pressure should not exceed 75PSI plus the lift pressure.
Cycle and run times should be decent as the tank is drained and refilled.

Thoughts?

a "CSV" setup does not "run full power" into a restriction. a motor at 60Hz spins at speed. if you restrict the output on any centrifugal pump/fan, amp draw (and thus power) will go DOWN. your peak power draw will be at peak flow. all you need is enough GPM through the pump to keep it from overheating. 1GPM is plenty.
You'll see more wear and tear on the pump from starting/stopping it than you will from running it continuously. especially in cases like lawn watering, where the pump is at high duty cycle, shutting it off to turn it on again moments later seems very silly.

I'm not an expert but 75psi seems awfully high for a well pump. Have you sourced a pump yet and checked max ratings? Its been a while since I looked into it, I recall 60 psi was a common max cutoff.

if you look at head on a deep well pump, the pressure range you set the switch for may be trivial compared to the head pressure the pump sees. I wouldn't worry about it.

 

[Showkey]

If you’re feeling a drop in flow, that’s because the captive pressure in the tank bladder hasn’t been tuned to the pressure switch setting - a surprisingly common mistake.

Whatever your cut-in pressure on the pressure switch, the pressure in the bladder should be set 2-3 psi lower. That has to be set with no water pressure in the system. In addition the accuracy of the pressure gauge found on most well plumbing systems is only accurate to a ballpark range, as are most folk’s air pressure gauges. To get the best performing system, a good plumber will cycle the system a handful of times, increasing or decreasing the tank bladder pressure and measuring the gallons of output before the pressure switch triggers. When you get it right, you get the most useful gallons out of the tank for.

With pressure tank set at 60-40 pressures ………its normal to feel the difference from 60psi and 40psi before the pump turns back on. The bladder tank pressure settings have absolutely nothing with feeing of low pressure because it’s actually low pressure 40 PSI at the cut in. Tuning the tank will not fix the perceived problem. If the pressure tank is very low pressure like 10-15 PSI low then the pressure difference issue will be exaggerated.

The 20 psi differential is a compromise, setting it lower means the pump start and stops far more often. Setting it higher makes the changing pressure more noticeable.

The fix is a constant pressure system as the OP is asking about. More complex and more expensive as already noted.

 

[firebirdparts]

I understand it fine.

There’s nothing wrong with what you propose. Do it and stop analyzing the system. The tank is a for controllability; water storage is in the well. Basic is good.

 

[N_Jay]

Yep, as an engineer I tend to overthink.
I don't mind putting in a little extra to get what I want, especially in things that are long term and you use/experience every day.
Saving $500 on the well system is nothing in the bottom line of the house, but if I don't then every shower I will be thinking "I should have", and for about 10 cents I could have.

 

[u3b3rg33k]

With pressure tank set at 60-40 pressures ………its normal to feel the difference from 60psi and 40psi before the pump turns back on. The bladder tank pressure settings have absolutely nothing with feeing of low pressure because it’s actually low pressure 40 PSI at the cut in. Tuning the tank will not fix the perceived problem. If the pressure tank is very low pressure like 10-15 PSI low then the pressure difference issue will be exaggerated.

The 20 psi differential is a compromise, setting it lower means the pump start and stops far more often. Setting it higher makes the changing pressure more noticeable.

The fix is a constant pressure system as the OP is asking about. More complex and more expensive as already noted.

I've lived most of my life on private wells. if things are adjusted properly, and you have the right kind of restrictors in your water outlets (faucets, showers), it's not that noticable, imho. and by that I mean pressure compensating restrictors/shower valves.

when we would do irrigation off the house well, we would try to run as many sprinklers as it took to keep it from cycling at all. often the restriction was the hose bib valve itself. that could be eliminated by replacing it with a ball valve, but those have to be removed in the winter.

 

[fitter30]

Cycle stop valve with small expansion tank work quite well by having the the valve set at 50 lbs and pump shut off switch set to 55 lbs. The pump stays running longer by having the pump run at shut off ( pump curve) last few pounds.

 

[mike93lx]

I've lived most of my life on private wells. if things are adjusted properly, and you have the right kind of restrictors in your water outlets (faucets, showers), it's not that noticable, imho. and by that I mean pressure compensating restrictors/shower valves.

when we would do irrigation off the house well, we would try to run as many sprinklers as it took to keep it from cycling at all. often the restriction was the hose bib valve itself. that could be eliminated by replacing it with a ball valve, but those have to be removed in the winter.

I had a ridiculous shower tower setup in my last master, with no restrictor. It was nuts and I wouldn't even shower with it on full tilt.

Never, at any point, did I notice the pressure change, and that is the kind of thing that would have bugged the **** out of me. I didn't have any kind of an elaborate setup either. I am really puzzled by all the concern over pressure changes. Maybe I got lucky?

 

[u3b3rg33k]

I've been in some more rural houses where it's more noticeable. when it gets close to cut-out it's pretty obviously stronger, and the bathroom lights flicker a tad when the pump kicks on. can't say the latter is comforting. I think that was a 30/50 system.

 

[thammel]

I run 40-60 psi and have a large well-x-trol tank. The larger the tank the less you will cycle your pump and you really won't notice the pressure change.

 

[Showkey]

when we would do irrigation off the house well, we would try to run as many sprinklers as it took to keep it from cycling at all. often the restriction was the hose bib valve itself. that could be eliminated by replacing it with a ball valve, but those have to be removed in the winter.

Me too…. on different well systems for 30 plus years…….no interest in flow restrictions especially in a shower. In fact run two shower head in the main bath

 

[Zebu Fellenz]

Thoughts?

How much water (GPM) are you expecting to pump from the well? Reason I ask is the higher the flow the more sense a constant pressure (variable speed pump drive system) makes. I have two wells with constant pressure systems (7.5hp pumps) that make around 100GPM each. For systems like this I'll argue that constant pressure pumps/controls are necessary to prevent hard starts, short cycling, huge pressure tanks, etc. And the system is cost competitive with other options.

For a smaller system (under 25GPM) there are still plenty of good options for constant pressure but IMO the benefits (small pressure tank, possibly longer system life, CONSTANT PRESSURE) might not be worth the additional cost.

Price out a Goulds ProPak kit to fit your pump depth and flow requirement. You'll probably be looking at over $1,000 more than a single phase pump and control box but it'll do exactly what you want and might not be much more expensive than regulators, extra tanks, etc.

https://www.aquascience.net/products/pumps-tanks-well-components/goulds-propak

 

[u3b3rg33k]

Me too…. on different well systems for 30 plus years…….no interest in flow restrictions especially in a shower. In fact run two shower head in the main bath

I mean, I've never encountered an unrestricted shower. there's always some part of the showerhead that is a restriction. most are 2.5GPM or less these days.

 

[MTY]

Not knowing your terrain, I will just throw this out. If you have a hill near the well you can pump to a cistern and gravity feed the house. It takes a lot of the hassle out of having a well. I have a well at the base of a hill and on the same flat the house sits on. I pump to a cistern on the hill, and gravity feeds the house. I do not have a pressure tank, and with a 2100 gallon cistern the well pump only kicks on every month to month and a half. Loss of power for a few days does not stop gravity from getting water to the house.
Outside water comes from a spring. It too feeds a 2100 gallon cistern. That system does have a small pump with tank on it.

 

[N_Jay]

Maybe the fields houses have always had bad tanks of mis-set pressure switches.
It is a typical 10GPH pump feeding one home. We will have some outside watering needs, but probably not even putting in a large lawn.
I think I might be convinced that I am overthinking it.
I will up the tank size as that seems to be a good investing for more stored water when the power is out and less pump cycling with longer on times.

 

[Showkey]

I mean, I've never encountered an unrestricted shower. there's always some part of the showerhead that is a restriction. most are 2.5GPM or less these days.

So to would be 5 gallons per minute if you chose to use two.

And some shower heads are too concerned about the conservation flow spec vs actually getting the job done.

And those that don’t want a restrictor in most faucets they are easily removed……..kitchen faucets are often modified because some have poor flow ( even the high end) . Modern Faucets can be like low flush toilets some can’t **** move the ****. While others are highly rated for flow and pressure drop.

 

[Bert_]

I've put one of the cycle stop valves in. They work well. Pumps burn up from excessive starts, constant run is best for them. Power use is related to flow, it's not a positive displacement pump.

 

[N_Jay]

I've put one of the cycle stop valves in. They work well. Pumps burn up from excessive starts, constant run is best for them. Power use is related to flow, it's not a positive displacement pump.

Power is "related" to flow, but at very low flows power per gallon starts going up.
I can't find curves for a 3/4 HP 10 GPM pump, but from other pump charts found peak efficiency is near the design flow rate, and efficiency is down about 15% at 60% flow, heading down even further as flow goes down.

 

[Bert_]

Power is "related" to flow, but at very low flows power per gallon starts going up.
I can't find curves for a 3/4 HP 10 GPM pump, but from other pump charts found peak efficiency is near the design flow rate, and efficiency is down about 15% at 60% flow, heading down even further as flow goes down.

It's not worth worrying about a 15% loss in efficiency. Pump doesn't use much power to begin with. Do what's best for pump life because it's a lot more expensive to replace a pump.

 

[N_Jay]

It's not worth worrying about a 15% loss in efficiency. Pump doesn't use much power to begin with. Do what's best for pump life because it's a lot more expensive to replace a pump.

That is 15% down at 6 GPM for a 10 GPM pump.
The curves continue to turn down, so probably 30% down at 3 GPM and 45% down at 1.5 GPM.
That is from peak efficiency of about 85% at 8 to 10GPM

 

[Bert_]

That is 15% down at 6 GPM for a 10 GPM pump.
The curves continue to turn down, so probably 30% down at 3 GPM and 45% down at 1.5 GPM.
That is from peak efficiency of about 85% at 8 to 10GPM

You are way overthinking this...

 

[N_Jay]

You are way overthinking this...

LOL, Why yes I am!~

 

[u3b3rg33k]

Yeah, lol. worry about efficiency by choosing a pump that makes sense, up front. as big as you need, as small as you can get away with, is often the right path (lowest cost - you can always water your lawn slower/longer). not by worrying about the CSV setup.