Pressure Tanks in Series

[Valveman]

With many small uses of water during the day the small tank can cause many cycles. But it is never more than the 100-300 cycles per day the motor manufacturers rate the motors to handle. (1HP and smaller 300, 1.5HP to 3HP 100 times per day) There are also many different ways to use water, even when just washing hands. Nobody washes their hands more than I do. I am a dirty boy, work hard, and wash my hands probably 100 times a day, sometimes with solvents as well. Lol. I have tested that when I leave the tap wide open during the hand washing, that I use 2-3 gallons for each wash at 1.5 GPM. But if I just trickle water to lather up, and turn off the faucet until needing to rinse, I can wash my hands 7-8 times with 1 gallon of water. Same thing applies when brushing my teeth.

I also have a open loop heat pump. I purposely undersized the HVAC so it would not cycle. I have seem many HVAC systems that are oversized and therefore cycle on for only a few minutes each time. If the heat pump is cycling, the well pump will have to cycle, regardless of the size of tank. If the heat pump only uses 20-30 gallons per cycle, an 80 gallon pressure tank (20 gallon draw) will cause the pump to cycle once per heat pump cycle. Even with a small pressure tank (1 gallon draw) the CSV would also cause the pump to cycle only once per heat pump cycle. The difference is the pump with the 80 gallon tank system would run about 2 minutes at full amp load to refill the tank during a 5 minute heat pump run. The pump with the CSV and small tank would run the entire 5 minutes the heat pump is on, but at about 50%-60% of full amp load.

You would think it best for the well pump to run only 2 minutes at full load amps and then shut off compared to running for 5 minutes. But that is not the case. The pump without the CSV runs at full amp load (max heat) for two quick minutes and then shuts off. It takes at least 1 minute for the motor heat that was created during pump start to dissipate into the water. That is why motor manufactures require a minimum of 1 minute of run time. But the motor stops while it is still hot, after running at full load amps for a minute or two. That is why motor manufacturers require at least 1 minute of off time, to let the motor cool before restarting. Motor manufacturers say 1 minute on and off is mandatory, 2 minutes is better, and running continuously is best.

It is much better for the motor to run for a longer period of time at reduced amperage. With a CSV the pump will run for the entire time the heat pump is running, plus one more minute to fill the tank. But depending on how much water is being used, the CSV will cause the motor amps to drop from 10% to 50% of max load. Amps reduced as little as 10% de-rate the motor load, making it run cooler. The more the amps are reduced by the CSV, the less heat the motor produces. The last minute needed for the CSV to fill the tank is at 1 GPM flow and the lowest amps possible for the particular pump. At such low amps, the motor is not hot when it shuts off. Therefore it also doesn't really need at least a minute to cool down before restarting. Although, restarting within a few minutes would be rare even with the small tank, as the 1 minute time delay off by the CSV made sure you were finished using water before the pump shut off.

Then, there is no reason why you can't use a CSV WITH the large 80 gallon tank, which gives you the best of both worlds. Any demand over 20 gallons is supplied without cycling the pump again. The CSV still gives the 1 minute (low amperage) motor cool down before the pump shuts off. There is another advantage of the CSV as the pump shuts off while filling the tank at a rate of 1 GPM instead of 10-20 GOM depending on the size of the pump. Shutting the pump off while pumping only 1 GPM eliminates the water hammer and damage done when the pump shuts off at full pump flow. At 10-20 GPM the check valve is wide open when the pump shuts off and the reverse of flow and slamming check valve will cause water hammer than shortens the life of many parts in the pump system. When the CSV is filling the tank at 1 GPM the check valve is only open a millimeter. There is no water hammer on pump stop, which makes check valves and many other things last much longer. Plus, with 20 gallons of water from an 80 gallon tank, the wife can wash hands as many times and any way she wants. However, over 30 years there have been many people in the same situation who ended up swapping out the large tank for the smaller one. They said they didn't notice much if any difference in how the well pump was working because of the CSV., which makes the large tank just a waste of money and space.

I appreciate the questions as I learn this stuff from my customers. They notice things like I mentioned above and ask how the CSV makes that happen. Then I have had to figure out how and why it works so well.

 

[MicEd69]

What is important is the pump does not cycle on and off WHILE water is being used.

This is THE issue that, to me it seems, many people are having a hard time to actually understand. I think lots of people who have never been on a well look at flow rates for a shower, the number of times someone flushes a toilet, the number of times some washes clothes, etc., and compare that to the volume of water in the pressure tank totally ignoring the flow rate of the water from the well.

From some discussions I've read, it seems to me that most people do seem to understand how a variable frequency drive works to accomplish less cycling of the well. It surprises me that they cannot apply that same logic to a CSV.

 

[MicEd69]

The pump without the CSV runs at full amp load (max heat) for two quick minutes and then shuts off. It takes at least 1 minute for the motor heat that was created during pump start to dissipate into the water.

And don't forget about the inrush current each time any AC motor starts. It can be like 3 times full load amperage.

 

[Valveman]

From some discussions I've read, it seems to me that most people do seem to understand how a variable frequency drive works to accomplish less cycling of the well. It surprises me that they cannot apply that same logic to a CSV.

I know right! I started with VFD's. That is where the Cycle Stop Valve came from. I was looking for something that did the same variable flow at constant pressure as a VFD, without being expensive, computerized, technical, and problematic like a VFD. We were using valves as a backup for the unreliable VFD's we installed. After observing that the amp draw was basically the same no matter if the VFD was reducing the motor speed or the pump was running at full speed and simply being restricted by a valve, the light bulb went off over my head. Figuring out the best way to make a little 1 GPM bypass took a little R & D, but the idea worked better and most importantly was more reliable than the VFD's we installed.

It is certainly one of the few truly counter intuitive things I know about. Most people have it in their heads that slowing a pump down with a VFD uses less energy and is easier on the pump. In the same way people think restricting a full speed pump with a valve burns energy and is hard on the pump. In reality just the opposite is true. Pumps like to run at full speed, as there are many downfalls to varying the speed. Restricting a pump with a valve decreases the amp draw, making the motor work easier and run cooler. Then, even though you can see the amps drop when a VFD slows down a pump, this is causing the pump to use more energy per gallon produced. I have had people get fighting mad with me over these statements. They are so blinded by their anger they won't look at a pump curve and see that I am correct.

As they say it is all about the Benjamin's. VFD's are expensive, short lived, and rarely repairable, which is a fluid product or cash cow for the manufactures. The fact that customers are wrongly convinced a VFD saves energy and is easy on the motor, makes the expensive and short lived VFD an easy sell. The fact that a simple, inexpensive spring operated valve can do a better job than a VFD is only understood by those who have been enlightened. I am just not as good at enlightening people as I could be.

 

[Ludington]

Just watched my well cycle along with my heat pump. Heat pump ran for 6 minutes 25 seconds. My well kicked on and ran for 3 minutes and 5 seconds. (About 4 minutes after hp start) well is a 10 gpm 2 wire 220v pump. Hp is using between 4.5 - 5 gpm. Well started at 1149 watts, and ended at 1114. A slight decrease along the way. Starting with 0 gpm use from house, and ending with 0 gpm. I see no significant difference in how the well drew its current. No big inrush of current (See graph of use)
I guess my question is since I see no difference in watts used from 0 gpm to 10gpm back to 0 gpm. Where does the reduction of watts happen using a cycle stop ? Also, checking my well over the last 24 hours, it cycled 27 times, with the shortest time between runs of 20 minutes, and the shortest run time of 3 minutes and the longest of 4 minutes. Got down to 24 degrees last night.. one of our colder nights. Hp pulls about 2500 watts.. included a graph of that too.
Tell me what I would see on my graph once the well pressure hits 50 psi on its way to 60. And I'm assuming it throttles the water flow to match the usage of 4.5 gpm at that point.

 

[Valveman]

And don't forget about the inrush current each time any AC motor starts. It can be like 3 times full load amperage.

Yes, thanks. I could go on and on about the benefits of the Cycle Stop Valve. But there are so many benefits it is hard to not make it sound like Snake Oil, as nothing should work that well. The many benefits of the CSV have always been there, I am just still trying to understand all of them. I certainly understand why many people are skeptics. That is why I always offer money back if you don't like it. What have people got to loose? If they don't like it send the CSV back for a refund and install a larger tank. It is still a "conventional" system, adding a CSV doesn't change that.

 

[Twowaxhack]

Just watched my well cycle along with my heat pump. Heat pump ran for 6 minutes 25 seconds. My well kicked on and ran for 3 minutes and 5 seconds. (About 4 minutes after hp start) well is a 10 gpm 2 wire 220v pump. Hp is using between 4.5 - 5 gpm. Well started at 1149 watts, and ended at 1114. A slight decrease along the way. Starting with 0 gpm use from house, and ending with 0 gpm. I see no significant difference in how the well drew its current. No big inrush of current (See graph of use)
I guess my question is since I see no difference in watts used from 0 gpm to 10gpm back to 0 gpm. Where does the reduction of watts happen using a cycle stop ? Also, checking my well over the last 24 hours, it cycled 27 times, with the shortest time between runs of 20 minutes, and the shortest run time of 3 minutes and the longest of 4 minutes. Got down to 24 degrees last night.. one of our colder nights. Hp pulls about 2500 watts.. included a graph of that too.

You trying to be a bully ? . Just agree and move on before you get lectured.

 

[Ludington]

You trying to be a bully ? . Just agree and move on before you get lectured.

No, absolutly no bullying... goodness no, just trying to understand and learn. If I'm comming a cross as argumentative, I apologize, just reporting on what I see, and again trying to get this old man (me) to understand.

 

[Valveman]

Just watched my well cycle along with my heat pump. Heat pump ran for 6 minutes 25 seconds. My well kicked on and ran for 3 minutes and 5 seconds. (About 4 minutes after hp start) well is a 10 gpm 2 wire 220v pump. Hp is using between 4.5 - 5 gpm. Well started at 1149 watts, and ended at 1114. A slight decrease along the way. Starting with 0 gpm use from house, and ending with 0 gpm. I see no significant difference in how the well drew its current. No big inrush of current (See graph of use)
I guess my question is since I see no difference in watts used from 0 gpm to 10gpm back to 0 gpm. Where does the reduction of watts happen using a cycle stop ? Also, checking my well over the last 24 hours, it cycled 27 times, with the shortest time between runs of 20 minutes, and the shortest run time of 3 minutes and the longest of 4 minutes. Got down to 24 degrees last night.. one of our colder nights. Hp pulls about 2500 watts.. included a graph of that too.

Those kind of meters average and time things out. Youi will not see peak start amps unless you have a "peak hold" feature on a meter. But in rush current is still there. That is why the lights flicker when the well pump or heat pump kick on. A pump that draws 1000W running will pull 6000W for a splint second on every start. There is a lot of heat in a quick pop start on the motor, which is one reason starting a pump too many times is not good. But soft starters are not good for submersible motors either, but that is another long explanation.

No, you won't see any amp or watt drop with a pressure tank only system. The little drop you do see is from the reduced flow from the pump as the pressure increases and/or the well water level decreases. Some pumps do this better than others. I will post a picture of a 1HP pump curve. You can see the power required at 15 GPM is like 1.4HP as submersibles work with that kind of service factor. But look at power required at 5 GPM flow like for your heat pump and you will see it has dropped about 40% to 0.8HP load (STILL AT FULL SPEED). But you will only see that with a CSV.

 

[Valveman]

No, absolutly no bullying... goodness no, just trying to understand and learn. If I'm comming a cross as argumentative, I apologize, just reporting on what I see, and again trying to get this old man (me) to understand.

Didn't see it as bullying. Good questions. Hope I answered them adequately.

 

[Twowaxhack]

No, absolutly no bullying... goodness no, just trying to understand and learn. If I'm comming a cross as argumentative, I apologize, just reporting on what I see, and again trying to get this old man (me) to understand.

Ok, but once you understand make sure you agree or it’s bullying.

It comes down to how much water the occupants use and the intervals the occupants use the water vs how much the little tank can supply before the pump turns on and subsequently back off making a complete “ cycle “.

There are assumptions being made until a cycle counter is installed to actually see what a system is doing. I’ve tested two systems and cycles didn’t go down, they went up.

 

[Valveman]

Just watched my well cycle along with my heat pump. Heat pump ran for 6 minutes 25 seconds. My well kicked on and ran for 3 minutes and 5 seconds. (About 4 minutes after hp start) well is a 10 gpm 2 wire 220v pump. Hp is using between 4.5 - 5 gpm. Well started at 1149 watts, and ended at 1114. A slight decrease along the way. Starting with 0 gpm use from house, and ending with 0 gpm. I see no significant difference in how the well drew its current. No big inrush of current (See graph of use)
I guess my question is since I see no difference in watts used from 0 gpm to 10gpm back to 0 gpm. Where does the reduction of watts happen using a cycle stop ? Also, checking my well over the last 24 hours, it cycled 27 times, with the shortest time between runs of 20 minutes, and the shortest run time of 3 minutes and the longest of 4 minutes. Got down to 24 degrees last night.. one of our colder nights. Hp pulls about 2500 watts.. included a graph of that too.
Tell me what I would see on my graph once the well pressure hits 50 psi on its way to 60. And I'm assuming it throttles the water flow to match the usage of 4.5 gpm at that point.

That power monitor is pretty cool. Been looking for one. Would it know if the freezer didn't come on for a certain period of time and be able to alert me?

Oh, and what brand of pump do you have? I will do the math.

 

[Ludington]

That power monitor is pretty cool. Been looking for one. Would it know if the freezer didn't come on for a certain period of time and be able to alert me?

Oh, and what brand of pump do you have? I will do the math.

The monitor is an emporia energy. Looks like around 150 bucks now.
It works really well. Except for 1 thing... if your watching the graph (by the second) when whatever your watching starts, you see everything, the starting spike and subsequent usage. But they changed it now so if you back the graph up they take what's used from when it starts to the next whole minute mark and average it.. so you get a flat line use for 60 seconds. Actually pretty useless. So you have to be watching to catch the starting spike. They do it for the last minute too. The minute, hour, day, week, month and year are accurate though. Attaching pics of each. The ones I attached earlier were from me watching and screen shooting it.
Oh, my pump is a country line from tractor supply. My well went out and it was the weekend so I couldn't be to pickey .
Oh, you attach a ceramic ring for each circuit you want to monitor in your breaker box.. (almost called it a fuse box... man, getting to old)

 

[Valveman]

Thanks. I get the same kind of graph with the little Wifi switches or breakers I have been using. It also only looks at the amps/watts every minute or so and averages things out. I need something that graphs amps/watts in real time at real quantities. You can't see the spikes and dips with the ones that I have found so far. That is important stuff when trying to see how a pump is working.

The County Line pumps seem to be pretty good. But I do not know who makes them and cannot find an efficiency curve. Probably not available. From the design I am guessing it has Horsepower characteristics similar to a Goulds and drops 30% or so in amperage. If you end up with a Cycle Stop Valve on that pump you can post the graph of the watts and tell us how much that pump decreases in amps when restricted with a valve.

 

[Ludington]

Thanks. I get the same kind of graph with the little Wifi switches or breakers I have been using. It also only looks at the amps/watts every minute or so and averages things out. I need something that graphs amps/watts in real time at real quantities. You can't see the spikes and dips with the ones that I have found so far. That is important stuff when trying to see how a pump is working.

The County Line pumps seem to be pretty good. But I do not know who makes them and cannot find an efficiency curve. Probably not available. From the design I am guessing it has Horsepower characteristics similar to a Goulds and drops 30% or so in amperage. If you end up with a Cycle Stop Valve on that pump you can post the graph of the watts and tell us how much that pump decreases in amps when restricted with a valve.

View attachment 43457

Emporia is pretty good if your watching real time, but sliding the graph back and looking at the seconds history does you no good. You can download back data up to a year, but real time shows the spikes and watts being pulled. Here is a couple more pics of my well just now..
I've seen different values for my start spike, so I'm thinking it's probably pretty close.
I think I found that countryline is made by pentair, I figured it was there low-end model.

 

[Valveman]

It would not surprise me that Pentair makes the County Line pump at TS. They make that pump with a dozen different names on it and tell their Pentair, Berkeley, Sta-Rite dealers they don't sell to end users or box stores. Lol! If it is a Pentair the amps will not drop very much. Using a floating stage impeller design for easy manufacturing with larger tolerances makes the impellers on that type pump drag the diffusers and draw more amperage. The floating stage design will only decrease in amperage maybe 10% when the flow is restricted, compared to 50% or 60% with the floating stack design used by other manufacturers. It won't make much difference on the electric bill for house water use or high flow irrigation, but would with small flow irrigation designs. The 10% drop in amperage is still enough to de-rate the motor load, causing the motor to run cooler when the flow is restricted.

A 1/2HP, 230V motor draws about 1000w or 6 amps when running. Locked rotor amps show to be 23 for a 3 wire motor and 33 for a 2 wire motor, which should make in-rush start current about 4000W or 5000w respectively. Amplitude and duration both play a part with in-rush currents on pump start. The start capacitor decreases amplitude on 3 wire motors, and the Cycle Stop Valve can decrease the duration with both 2 wire and 3 wire motors. Basically, starting a pump against pressure as with a closed or almost closed valve like the Cycle Stop Valve greatly decreases how long it takes the pump to getup to speed. This also makes it important to have only one check valve on the pump itself with a submersible pump system.

 

[Ludington]

It would not surprise me that Pentair makes the County Line pump at TS. They make that pump with a dozen different names on it and tell their Pentair, Berkeley, Sta-Rite dealers they don't sell to end users or box stores. Lol! If it is a Pentair the amps will not drop very much. Using a floating stage impeller design for easy manufacturing with larger tolerances makes the impellers on that type pump drag the diffusers and draw more amperage. The floating stage design will only decrease in amperage maybe 10% when the flow is restricted, compared to 50% or 60% with the floating stack design used by other manufacturers. It won't make much difference on the electric bill for house water use or high flow irrigation, but would with small flow irrigation designs. The 10% drop in amperage is still enough to de-rate the motor load, causing the motor to run cooler when the flow is restricted.

A 1/2HP, 230V motor draws about 1000w or 6 amps when running. Locked rotor amps show to be 23 for a 3 wire motor and 33 for a 2 wire motor, which should make in-rush start current about 4000W or 5000w respectively. Amplitude and duration both play a part with in-rush currents on pump start. The start capacitor decreases amplitude on 3 wire motors, and the Cycle Stop Valve can decrease the duration with both 2 wire and 3 wire motors. Basically, starting a pump against pressure as with a closed or almost closed valve like the Cycle Stop Valve greatly decreases how long it takes the pump to getup to speed. This also makes it important to have only one check valve on the pump itself with a submersible pump system.

Watching my well, it's a 230 / 2 wire sitting 40 feet down. But I don't seem to have that big inrush, 1300 watts then down to 1100 running. Seems pretty consistent. My heat pump compressor shows a 4500 spike then down to about 2200 running. So it looks like the monitor is catching the spike. Hopfully it's accurate.

 

[markinnc]

Everyone, this is really fascinating stuff and I am learning a lot! My original fundamental question was never really answered. I see no evidence that a CSV will make my 17 year old Amtrol pressure tank any younger :>). I lost my well, my HVAC, and have property taxes due all within two weeks. My wallet is running dry! I was not asking about a CSV (system optimization) but about the risks of delaying further upgrades to the system and exploring an inexpensive fix (add a tank) to get me by until a CD matures in May. I saw a debate online (Youtube) about someone putting in a second tank with PVC and a t-connection (no pressure relief valve, drain)...

Cary in our phone conversation you identified I could use your $255 Cycle Monitor. I found a Symcom Pumpsaver for $158 (discounted) without an enclosure ($12 on Zoro), I also see some home automation smart switches which might be able to get the job done but don't have a smart home. In 34 years, I do not believe our well has ever gone dry, even during drought. Is there an inexpensive motor saver type cut out that I could use?

A fundamental question I was asking (do nothing) is if I simply wait for my wallet to fill back up, what is the risk to my new pump if the tank fails?

I am generally investigating whether it is feasible to stage the repair by adding a tank and then redoing everything correctly in May. It seems that a CSV would make the Home Depot inexpensive Water Worker an acceptable primary tank? I would greatly appreciate basic advice from the community on my cash flow challenged situation.

 

[Ludington]

Everyone, this is really fascinating stuff and I am learning a lot! My original fundamental question was never really answered. I see no evidence that a CSV will make my 17 year old Amtrol pressure tank any younger :>). I lost my well, my HVAC, and have property taxes due all within two weeks. My wallet is running dry! I was not asking about a CSV (system optimization) but about the risks of delaying further upgrades to the system and exploring an inexpensive fix (add a tank) to get me by until a CD matures in May. I saw a debate online (Youtube) about someone putting in a second tank with PVC and a t-connection (no pressure relief valve, drain)...

Cary in our phone conversation you identified I could use your $255 Cycle Monitor. I found a Symcom Pumpsaver for $158 (discounted) without an enclosure ($12 on Zoro), I also see some home automation smart switches which might be able to get the job done but don't have a smart home. In 34 years, I do not believe our well has ever gone dry, even during drought. Is there an inexpensive motor saver type cut out that I could use?

A fundamental question I was asking (do nothing) is if I simply wait for my wallet to fill back up, what is the risk to my new pump if the tank fails?

I am generally investigating whether it is feasible to stage the repair by adding a tank and then redoing everything correctly in May. It seems that a CSV would make the Home Depot inexpensive Water Worker an acceptable primary tank? I would greatly appreciate basic advice from the community on my cash flow challenged situation.

Grundfos has dry well protection built in... if that helps....
I dont think anything helps prevent short cycling when a tank fails..
Please correct me if I'm wrong here. But if your going to add a second tank, why not just replace the original one now (if your afraid of it)

 

[Twowaxhack]

You can buy a low pressure resettable pressure switch for about $40.

If the pressure drops too low it’ll cut your system off until you reset it.