Water Well Pump Monitor???

[Xfaxman]

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One key thing to understand is, the pump does not run at full RPM and full current draw, it only runs fast enough, using only enough current to provide the required flow.

Thanks for that excellent explanation Xfaxman. It was almost perfect, except for the part about the pump not running at full RPM. The current draw does decrease, the same as if you had slowed the RPM of the pump, but you don't have to reduce the RPM of a pump to get the amps to decrease. The amps of a pump/motor decrease naturally when the flow is restricted. So the CSV just restricts the flow from the pump, and the amps decrease on there own. All centrifugal type pumps do this. It is one of the most counter-intuitive things about pumps. You would think restricting the flow from a pump would make it work harder, not easier. But just the opposite is true.

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If the flow is restricted, the RPMs are less than maximum. Flow and RPM are directly proportional. The amps decrease because the pump motor is not running at max power and RPM, it is only running fast enough to produce the required flow. Power used = work done.

That is my understanding, correct me if I am wrong.

 

[Valveman]

If the flow is restricted, the RPMs are less than maximum. Flow and RPM are directly proportional. The amps decrease because the pump motor is not running at max power and RPM, it is only running fast enough to produce the required flow. Power used = work done.

That is my understanding, correct me if I am wrong.

Yeah that is why even many pump engineers don't understand this. It just doesn't make sense, but that is just the way any centrifugal pump works. The speed or the RPM of the motor is regulated by the frequency of the incoming power. 60 hz is full speed. And 60 hz is what comes from the power company, at least in the US. So unless you add an additional (variable frequency drive) to control the motor, the motor is always running at full speed or RPM. However, the centrifugal impeller is a pretty magical thing. Even though the speed of the pump does not decrease, the amp draw decreases with the flow rate, and is indirectly proportional to the back pressure or head. This is one of the few really counter-intuitive principles that I know of. It is hard to understand, and many people will add an expensive variable frequency drive because they do not understand that amps or power consumption is reduced naturally, without reducing the speed.

To make this even more confusing, the speed of a 60 hz pump actually increases when the flow is restricted with a valve, and the amps still go down. Depending on the number of poles in the motor winding, 60 hz power is trying to spin the motor at 3600 RPM. But when running at full load, there is what is called "slip" of about 4% in those kind of motors. This means the electrical field in the winding is spinning 3600 RPM, but the rotor is pulling the load and is not quite able to keep up and only spins at 3450 RPM. When the flow from the pump is restricted with a valve and the load decreases, the slip also decreases from 4% to about 2%. This increases the actual speed of the motor from 3450 to 3528 RPM, but the amps still go down.

Fans are a lot like pumps so you can test this by using a hair dryer. If you put your hand over the end of the dryer and block the flow, it is easy to hear the motor speed up, as there is no load on it. If you have an amp meter you can see that the amps still reduce when the dryer speeds up, same as a pump.

Even though the motor speeds up when the pumps flow is restricted, the motor is more efficient and running cooler. Less slip means the rotor is crossing fewer lines of flux. This reduces heat and makes the motor more efficient. Added to the reduction of load from the pump itself, causing lower amp draw, the motor runs much cooler, and requires less cooling flow.

Sorry! But you can see why this can be so confusing even pump engineers don't understand it.

 

[Xfaxman]

Well where I went wrong is comparing it to the hydraulic pumps that I am familiar with, where Flow and RPM are directly proportional.

Have had water wells most places I have lived, but never got into centrifugal pump internal operation.

Thanks for clearing it up. :thumbsup:

 

[dickfoster]

Your flow maybe "slow". But even people I know that really conserve water use at least 100 gallons per day. The average house with no outside or extra uses of water still uses an average of 300 gallons per day.

Your 12 gallon tank only holds 2 gallons of water. The 20 or 30 gallon tank you think you need only hold 5 and 7 gallons respectively. What good is a tank that holds 5 or 7 gallons of water in a house that uses and average of 300 gallons per day? The pump would still have to come on (cycle) 60 times a day to refill that 20 gallon tank for a 300 gallon per day house. Your water comes from the pump and well, not the pressure tank. You have millions of acre feet of water stored in the ground waiting for you to need it. All a pressure tank has ever been for, is to reduce the number of times per day the pump has to start (cycle) to supply the water you need. So when you have a CSV to eliminate the cycling, you don't need a very large tank.

With a system like the one Xfaxman described that uses water for hours at a time, it is easy to see the advantage of a Cycle Stop Valve. It just keeps the pump running continuously as long as the water is being used, instead of cycling dozens or hundreds times to produce the same amount of water.

With a home that has "slow flow" or doesn't use much water, it is harder to explain. The 1 gallon in the small tank must be used before the pump will start. So re-filling ice makers and washing hands won't cause the pump to start. The pump will have to come on to refill a 1.6 gallon flusher. But if you stand there and flush 100 times in a row, the CSV just keeps the pump running until you stop doing that. If you only flush once, 30 times per day, the pump will cycle 30 times per day. However, with a CSV the pump only cycles once for a long shower or to fill the washing machine. This eliminates 50 cycles per day, so the overall cycles are still less than if you have a larger tank and no CSV.

There are many benefits to eliminating all those pump cycles. The CSV creates stronger constant pressure in the shower, causes washing machines to fill faster, eliminates water hammer from the pump, etc. But being able to use a much smaller and less expensive tank, and making the entire pump system last longer are some of the best reasons for a CSV.

I think the primary reason for a so called pressure tank (an accumulator for all practical purposes) is to provide a constant water pressure to the plumbing system so you can take a decent shower. That said I put in 5000 gallons worth of tank last summer. That eliminates the pump cycling problem for the well pump all by itself although I added a pressure pump to the tank and still have the accumulator under the house.
There are several reasons to have an ample supply of water above ground, #1 is you can't fight much of a fire with a well pump alone, especially when the power is probably out. Also if and when the well or well pump develops some kind of a problem, we still have enough water to deal with the problem without having to move into a motel or something. 5000/300= about 16 days to get something done. More if we cut back and ration as we probably would.

 

[Valveman]

I think the primary reason for a so called pressure tank (an accumulator for all practical purposes) is to provide a constant water pressure to the plumbing system so you can take a decent shower. That said I put in 5000 gallons worth of tank last summer. That eliminates the pump cycling problem for the well pump all by itself although I added a pressure pump to the tank and still have the accumulator under the house.
There are several reasons to have an ample supply of water above ground, #1 is you can't fight much of a fire with a well pump alone, especially when the power is probably out. Also if and when the well or well pump develops some kind of a problem, we still have enough water to deal with the problem without having to move into a motel or something. 5000/300= about 16 days to get something done. More if we cut back and ration as we probably would.

Hi Dick
A 5000 gallon storage tank will keep the well pump from cycling more than once a day, but there is a trade off to everything. Now you have to pump the same water twice, which uses almost twice as much energy, uses twice as many pumps, and has twice as much expense and repair. Then you no longer get water fresh from the well, but water that has been sitting in a tank getting warm and stale for 15 days. Most people have to add chlorine on a regular basis to keep stuff from growing in the tank water. Not only does chlorine taste bad, but it is toxic. Water straight from a good well rarely needs any treatment, and is always fresh and cool.

You also just moved your cycling problem from the well pump to the booster pump. The pressure tank does not provide constant water pressure, as it is continuously changing from 40 to 60 and 60 to 40 PSI as the pump cycles and the tank fills and empties. It would also be very rare for anyone to have a pressure tank large enough to take a shower. A 44 gallon size pressure tank only holds 12 gallons of water. Even with that large a pressure tank it would probably have to fill and drain 3-4 times for the average shower. A booster pumping from a storage tank can benefit from a CSV just as much as a well pump. It will stop the cycling, deliver a constant 50 PSI to the shower (no matter how long a shower), and can do all of this with a very small pressure tank (accumulator). You don't want the booster pump to cycle itself to death, or you will have 5000 gallons of water you have to dip out with a bucket to use.

You need to put some kind of low water alarm in the storage tank, because most people don't find out their well pump has quit until it is too late and the storage tank is already empty.

Storage tanks are somewhat of a necessity with a low producing well. But a pump in a well that makes ample water could be fitted with a CSV. This way you would eliminate the well pump cycling, have constant pressure in the shower, and the well is much less likely to develop some kind of a problem that would leave you out of water.

Even with a storage tank, your water comes from the well not the storage tank or the pressure tank. If the well pump quits, your out of water. The storage may buy you a day or two, but you are effectively out of water until the well pump is repaired.

A storage tank is required in some areas for fire protection. But a generator for a good producing well would actually give you more water to fight a fire, because you would not be out after 5000 gallons. I would prefer an earth tank with a gas powered pump to fight fires. You could also use the same kind of 5000 gallon tank with a gas powered pump just to fight fires. That way it doesn't matter if the water gets slimy and green, it will still put out a fire, and you don't have to use that stale water in the house.

 

[dickfoster]

Hi Dick
A 5000 gallon storage tank will keep the well pump from cycling more than once a day, but there is a trade off to everything. Now you have to pump the same water twice, which uses almost twice as much energy, uses twice as many pumps, and has twice as much expense and repair. Then you no longer get water fresh from the well, but water that has been sitting in a tank getting warm and stale for 15 days. Most people have to add chlorine on a regular basis to keep stuff from growing in the tank water. Not only does chlorine taste bad, but it is toxic. Water straight from a good well rarely needs any treatment, and is always fresh and cool.

You also just moved your cycling problem from the well pump to the booster pump. The pressure tank does not provide constant water pressure, as it is continuously changing from 40 to 60 and 60 to 40 PSI as the pump cycles and the tank fills and empties. It would also be very rare for anyone to have a pressure tank large enough to take a shower. A 44 gallon size pressure tank only holds 12 gallons of water. Even with that large a pressure tank it would probably have to fill and drain 3-4 times for the average shower. A booster pumping from a storage tank can benefit from a CSV just as much as a well pump. It will stop the cycling, deliver a constant 50 PSI to the shower (no matter how long a shower), and can do all of this with a very small pressure tank (accumulator). You don't want the booster pump to cycle itself to death, or you will have 5000 gallons of water you have to dip out with a bucket to use.

You need to put some kind of low water alarm in the storage tank, because most people don't find out their well pump has quit until it is too late and the storage tank is already empty.

Storage tanks are somewhat of a necessity with a low producing well. But a pump in a well that makes ample water could be fitted with a CSV. This way you would eliminate the well pump cycling, have constant pressure in the shower, and the well is much less likely to develop some kind of a problem that would leave you out of water.

Even with a storage tank, your water comes from the well not the storage tank or the pressure tank. If the well pump quits, your out of water. The storage may buy you a day or two, but you are effectively out of water until the well pump is repaired.

A storage tank is required in some areas for fire protection. But a generator for a good producing well would actually give you more water to fight a fire, because you would not be out after 5000 gallons. I would prefer an earth tank with a gas powered pump to fight fires. You could also use the same kind of 5000 gallon tank with a gas powered pump just to fight fires. That way it doesn't matter if the water gets slimy and green, it will still put out a fire, and you don't have to use that stale water in the house.

I know all of this but I mainly wanted the protection offered by the tanks. Oh yeah recheck your math, I figure 16 days at least. I go up and bang on the tanks to ensure they are topped up. That's all the alarm I need. Protection as in fire and being without water.
Also I have the tanks installed uphill from the house so even if the pressure pump is off, a smaller pump BTW, I still get 10PSI at the house we can flush toilets, wash dishes and clothes and take a navy shower. For the full experience of being without water, just go trip the breaker for your well pump and wait. How long before the wife begins to howl? LOL

BTW As an Ex boy scout, I have a generator too. However a well pump pump doesn't deliver enough volume to do diddly to a real fire. The FD needs water and lots of it. I've been thinking of a gas pump too or maybe now even something PTO driven for the tractor. Oh sure I could have saved a few nickels and dimes, one always can but I could also let my house burn down for lack of water or even my neighbors house for that matter, waiting for the FD to haul water. Heck there's a lake full of it just 3 miles down a twisting winding road so why not just wait, save myself all those nickels and hope the house doesn't burn down while they are gone for more water. I think I'd rather spend money on this kind of insurance because it's real insurance not something some slick talking salesman sold me and I kept paying for hoping never to collect.

 

[Valveman]

Well I hope I didn't offend you is some way. There is nothing wrong with the set up you have, except that your booster pump is still cycling on and off frequently. But if I had to supply water storage for fire protection, the storage tank would be just for fire protection. I wouldn't want my house water sitting in a tank for so long. My well pump has a CSV, so the pump is not going to cycle itself to death prematurely. And with a generator for power outages, my well water is very reliable.

And if you have a float switch in the storage tank to control the well pump, it is very dependable. It is so dependable that people eventually forget to go bang on the tank. Then all of a sudden it is empty, you find out the well pump has been out for days, and you are in the same boat as someone with a well pump that needs replacing.

A low level alarm in the storage tank is an inexpensive safety device, and it doesn't forget to bang on the tank. There are lots of ways to skin a cat or install a pump system, and everybody thinks theirs is the best. I have just installed a few bazillion of these, and am just trying to offer my experience. I hear from people everyday who say, "you told me this would happen some day, and you were right, today is that day".

 

[dickfoster]

Well I hope I didn't offend you is some way. There is nothing wrong with the set up you have, except that your booster pump is still cycling on and off frequently. But if I had to supply water storage for fire protection, the storage tank would be just for fire protection. I wouldn't want my house water sitting in a tank for so long. My well pump has a CSV, so the pump is not going to cycle itself to death prematurely. And with a generator for power outages, my well water is very reliable.

And if you have a float switch in the storage tank to control the well pump, it is very dependable. It is so dependable that people eventually forget to go bang on the tank. Then all of a sudden it is empty, you find out the well pump has been out for days, and you are in the same boat as someone with a well pump that needs replacing.

A low level alarm in the storage tank is an inexpensive safety device, and it doesn't forget to bang on the tank. There are lots of ways to skin a cat or install a pump system, and everybody thinks theirs is the best. I have just installed a few bazillion of these, and am just trying to offer my experience. I hear from people everyday who say, "you told me this would happen some day, and you were right, today is that day".

Nope, nothing much bothers me.
My pressure pump doesn't cycle any more than the well pump once did as it has the same accumulator on it that the well once did. I think it holds something like 16 gallons or something along those lines. A tap opens, the bladder goes down after a bit then the pressure switch trips and calls for the pressure pump to pump it up again to keep the line pressure where I have it set. About 60 PSI I think it is, on the high side of normal for household water pressure.

Yeah there is a hi/low float switch in the tank and there is also protection on both pumps. I actually did some other things and added some valves etc. that the well guy didn't think of, like a way to bypass the tank and put the house back directly on the well. I also put a bypass valve from the bottom of the tank so if the power is out I don't have to siphon though the pressure pump. Things to make service without interruption easier.

 

[Valveman]

Nope, nothing much bothers me.
My pressure pump doesn't cycle any more than the well pump once did as it has the same accumulator on it that the well once did. I think it holds something like 16 gallons or something along those lines. A tap opens, the bladder goes down after a bit then the pressure switch trips and calls for the pressure pump to pump it up again to keep the line pressure where I have it set. About 60 PSI I think it is, on the high side of normal for household water pressure.

Yeah there is a hi/low float switch in the tank and there is also protection on both pumps. I actually did some other things and added some valves etc. that the well guy didn't think of, like a way to bypass the tank and put the house back directly on the well. I also put a bypass valve from the bottom of the tank so if the power is out I don't have to siphon though the pressure pump. Things to make service without interruption easier.

Those are all good things. I would have done the same thing to be able to use the well pump directly and to get gravity feed from the storage tank when needed.

That said I put in 5000 gallons worth of tank last summer. That eliminates the pump cycling problem for the well pump all by itself

Your 5000 gallon storage tank stopped the cycling on the well pump, but now the booster pump is cycling as much as the well pump use to do. People don't think there pump cycles very much. But when you pin them down to a time, they will say, "oh it only cycles every couple of minutes". Well there are 1440 minutes in a day. Do the math and you can see how many times per day or hour the pump is cycling. Adding several big pressure tanks will reduce the cycling, but that makes the pressure fluctuations worse, as the pressure stays lower for longer. If you stop the booster pump from cycling, the pressure in the house will be much better, and the pump will last longer so you won't have to resort to those emergency conditions where you run directly from the well or gravity from the storage tank.

 

[dickfoster]

Those are all good things. I would have done the same thing to be able to use the well pump directly and to get gravity feed from the storage tank when needed.



Your 5000 gallon storage tank stopped the cycling on the well pump, but now the booster pump is cycling as much as the well pump use to do. People don't think there pump cycles very much. But when you pin them down to a time, they will say, "oh it only cycles every couple of minutes". Well there are 1440 minutes in a day. Do the math and you can see how many times per day or hour the pump is cycling. Adding several big pressure tanks will reduce the cycling, but that makes the pressure fluctuations worse, as the pressure stays lower for longer. If you stop the booster pump from cycling, the pressure in the house will be much better, and the pump will last longer so you won't have to resort to those emergency conditions where you run directly from the well or gravity from the storage tank.

I think I'm fine as things set now. I got the protection and reserve capacity I wanted. As a retired engineer, I know when it time to stop engineering before someone decides to shoot the engineer. LOL