constant pressure system

Discussion in 'Pumps and Tanks Well Forum & Blog' started by bigballer, Aug 28, 2006.

  1. bigballer

    bigballer New Member

    Messages:
    9
    Location:
    Seattle, WA
    my new well should produce 12-15gpm and i am considering a 3 phase motor with controller (goulds gs 1-1.5hp with balance-flow controller). the pressure tank is 4.5gallons. i should consider some light irrigation in the summertime as well but water is mainly being used for household usage, washer, dishwasher, showers, etc. 2 adults, no kids, a few horses in pasture and 4 dogs. my well is 130ft deep and is roughly 350ft from the wellhouse where the pressure tank will be. i will run 1" 200psi poly and 12/3 to the pump from the wellhouse and 10/3 from the panel in the wellhouse to the main panel in the garage. the only other power draw would be a light in the well house.

    wondering what the advantages are to these constant pressure systems when considering longevity, performance, stability and pressure.

    does this sound like a good setup?

    cheers,
    bigballer
  2. speedbump

    speedbump Previous member

    Messages:
    4,540
    Location:
    Riverview, Fl.
    Check out Cycle Stop Valves as opposed to the constant pressure pumps. You will save money and have a more dependable system. There are a lot of discussions going on about this topic as we write.

    bob...
  3. valveman

    valveman Moderator Staff Member

    Messages:
    4,369
    Location:
    Lubbock, Texas
    Valveman

    Last year they made everyone send back their Balance Flow controllers to get a new computer chip installed. So the ones they are selling now have less than a year track record. If any of these are still working in five years I would be amazed. Buy a three phase motor, and decide you don't like the variable speed controller, now you got to buy a new single phase motor. 4.5 gallon tank actually holds about a gallon of water, pump has to come on everytime you flush a toilet. The most recent problem I am hearing from installers is that when the sprinkler system comes on, the one gallon in the tank is gone in seconds, the BF controller has a slow start so it takes a while for the sprinklers to start squirting. Mean time the bladder in the tank has bottomed out, pressure is low, pipes start shaking and rattling, lot of noise heard in the house. One installer said he has to strap all the pipes down to the floor or walls just to keep them from breaking. Also variable frequency controllers send out a radio signal that blocks AM radio, cell phones, and causes static lines on you TV. This radio signal that escapes is called stray voltage. They are just finding out that this stray voltage is causing dairy cattle to get sick and produce 20 to 30% less milk. Stray voltage also effects egg production, pork production, etc. There are atleast a dozen more negative side effects of variable speed pumps. You can read more about them at www.cyclestopvalves.com. We are very well educated on variable speed pumps that is why we no longer use them. In 1993 we discovered a way to get better performance and still produce a constant pressure at variable flows by using a simple and dependable valve. A VFD is a computer that controls your pump. How dependable do you think you water supply would be using computerized controls? Use a standard pump, little larger pressure tank (20 gal size holds 5 gallons of water), single phase motor and control, and a Cycle Stop Valve to provide the constant pressure. Simple controls make dependable pump systems. Nothing is more annoying than waking up to no water coming out of the faucet.
  4. abikerboy

    abikerboy DIY Senior Member

    Messages:
    202
    Location:
    VA
    Dont know anything about rumors started to sell valve, but have a real world article available in local newspaper. The farm in question is my next door neighbor. The power company installed a high tension tower 5 years ago. As soon as the new tower and power lines went into operation, all of his livestock became sick, lost appetites, low milk production, etc. Several animals even developed tumors. A local vet listed through the farm bearough suggested that the rf frequencies from the new power lines were causeing problems, so the farmer closed off part of his field. The animals became healthier, production went up, and because of that, I got a super nice deal on some extra land!
    Last edited by a moderator: Jun 5, 2007
  5. valveman

    valveman Moderator Staff Member

    Messages:
    4,369
    Location:
    Lubbock, Texas
    Valveman

    Thanks abikerboy. That is an interesting story. I have heard of several similar situations. Google (stray voltage VFD). You will see that there are several papers out there that describe stray voltage being produced by variable speed controls. What I don't see is anyone talking about the accumulative effect of multiple VFD's in the same area. When you have a VFD on the milking maching (which I think is a good idea and saves energy), and another VFD on a feed grinder or conveyor belt system, then you add a couple more on the water well pumps and a booster pump or two, then all the harmonics and stray voltage have an accumulative effect. These accumulating harmonics and stray voltages are very hard if not impossible to filter out. This can cause the same problems as high voltage transmission lines like the ones abikerboy describes. The only solution I know of is to limit the number of VFD's on location. Never use a VFD if there is any other way of accomplishing the task. Then use good harmonic filters on any VFD still in use along with extra grounding of the electrical system. Now we need to figure out what stray voltage is doing to people in the home environment. Anything that causes tumors in cattle could certainly cause the same to humans. Some washing machines now have VFD controls. Treadmills and other appliances use variable speed controls. Now if you add one to your home water system, we are talking accumulative effect. Again the best way I see is to not use a VFD if there is any other way to accomplish the task. The CSV is completely mechanical. It has no electronics or rapid switching devices that produce harmonics or stray voltage. Since the CSV is actually a better way of controlling pumps than a VFD, that is one less producer of stray voltage to have to worry about. Now if we use a washing machine with standard motor controls and actually go for a walk instead of using a treadmill, the home environment becomes even safer.
  6. speedbump

    speedbump Previous member

    Messages:
    4,540
    Location:
    Riverview, Fl.
    I have heard of such things happening. Just like the chain link fence running parallel with high tension lines. The chain link fence acts like the secondary winding in a transformer. You open the gate with the other hand on the gate post and you can become a giant fuse.

    They still don't know what damage we may be doing to our brain with RF from cell phones. So I wouldn't be to quick to say this sort of thing is not happening.

    I do understand manufacturers of certain RF producing items wanting to poo poo the whole thing.

    kf4mm
  7. Gary Slusser

    Gary Slusser That's all folks!

    Reminds me of the debate concerning; long run out landslides, no life on the bottom of the oceans, 1000'+ tsunamis!, helicobacter bacteria causes stomach ulcers?, DDT is good for you, copper and brass is the best materials for potable water lines and 'bury it and it's gone forever' junk science we lived under for decades while ordinary folks reporting the phenomena where considered as stupid rednecks. That also included the few scientists/engineers saying otherwise for a decade or longer that were shunned out of their careers.

    Now it's adding fluoride and ammonia to our chlorine laced drinking water... as *they* tell us "we have the best water in the world". All the while most of us are walking around with a water bottle in our hip pocket, or buying water filters, to the tune of a few billion dollars a year in just the last 10-15 years. But I wouldn't go with a 3 phase or variable speed pump if they were gven to me. I'd buy a regular/common single phase pump and inexpensive CSV.
    Last edited: Aug 30, 2006
  8. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

    Messages:
    2,713
    Location:
    Central Florida
    I grew up living under a 440KV (I think) highline right across the road. I'm blaming my Alzheimer's on that. I have known people that lined various pieces of clothing with tinfoil, but it wasn't obvious that it did them any good:D .
  9. alternety

    alternety Like an engineer

    Messages:
    650
    Location:
    Washington
    This has been an interesting thread. Having a 3 phase pump I now know why the goldfish have been walking around and the rabbits all have 5 legs.
  10. valveman

    valveman Moderator Staff Member

    Messages:
    4,369
    Location:
    Lubbock, Texas
    Valveman

    The harmonics from a VFD are fed back into the electric grid. If you have a VFD with 6 switch operations, then all harmonics not divisible by 6 (7th, 9th,11th, 13th, etc.) are forced back into the incoming power supply. I am sure the VFD machine itself can broadcast radio frequencies but, the harmonics fed back into the power supply can use the incoming power wires as an antenna. Most insulated electric wire in a house has 600 Volt insulation. A 240 volt VFD produces voltage spikes of up to 1000 volts and a 480 volt drive produces spikes of 2000 volts. Your 600 volt insulated wires can't hold back these 1000 volt spikes and they leak out anywhere they can. Also you would have to use wires that have metal or copper shields properly grounded around them to hold in the radio frequencies. Otherwise any or every wire in or around your home can be transmitting radio frequencies from the VFD. Why else would AM radios stop working when you just get close to the area? Your neighbors VFD could actually be affecting you. I also disagree that the motor will outlast him because it can't tolerate the 1000 volt spikes from the VFD for very long either. Not to mention that reducing the speed of the pump/motor causes it to go through the mechanical frequency of every component in the pump/motor. At standard 3450 RPM these mechanical frequencies have been balanced out. But at 3120 RPM the motor shaft vibrates. At 3266 RPM the laminations in the motor vibrate. At 3289 RPM the impeller vibrates and so on. Its like driving a car with one unbalanced tire. Even though the tire is what is unbalanced it shakes the whole car and eventually the car starts falling apart. Then there is the "skin effect". Radio frequencies, which is what the motor runs on when using a VFD, travel on the skin of wire unlike regular AC voltage which travels in the core of the wire. When this radio frequency leaks out of the wiring it then travels on the skin of the equipment such as steel pipe and fittings, pump and motor casings, etc. It causes damage that looks like electrolysis, which is the soft particles in the metal dissolving into the water. Then there is the excess heat buildup in the motor from operating on harmonic frequencies and EDM currents that require motor shafts to be grounded to prevent bearing failure. I could go on with other negative side effects of the VFD. We stopped using VFD's in 1992. We realized back then that anything we did to help solve these problems was just a band aid. The root of the problems can't be fixed unless you can change the laws of nature. We built the Cycle Stop Valve in 1993 to simulate the control of a VFD without causing all the negative side effects of VFD. It turned out to be a very simple thing to do. When we realized that we got the same power reduction by using a valve to control a normal full speed pump as they get when slowing the RPM with a VFD, everything else was just icing on the cake. No matter how they try to tell you that the VFD is the most advanced technology, the Cycle Stop Valve is newer and more advanced because it can do more with less.
  11. valveman

    valveman Moderator Staff Member

    Messages:
    4,369
    Location:
    Lubbock, Texas
    Valveman

    This post has gotten long but is still on the original subject. The person with the original question didn't realize he was starting such a complicated subject. That is kind of the point. VFD systems have so many complications that very few people understand them all. I learned what I know about VFD the hard way. I experienced the problems in the field, then I researched the subject until I figured out what caused the problem. This was pre Internet days and was much harder to get the information needed. These days people can easily search the web for this information. I could explain these things for you but I took the time to find a few links so you could read it in someone else's words. There are many more articles on the web that will give you the real story, not just the white washed version that is in brochures of those who sell VFD's.

    "Wire insulation breakdown voltages have nothing to do with anything. If you exceed the insulation breakdown voltage you have really screwed up the design and the system will fail."
    "This causes very high turn-to-turn voltages which can produce premature insulation breakdown." http://findarticles.com/p/articles/mi_m0BPR/is_10_17/ai_66216307

    "There are no 1000V spikes inherent in a VFD. If they were generated by the switching devices (e.g., opening an inductive [motor] load, the electronics must eliminate them or the switching devices would generally fail. This is usually accomplished by a reverse diode across the switching device to dump the resulting energy spike."
    "This creates a severe voltage spike in the source, in this case the output transistors of the VFD, which can immediately cause them to short from dV/dt (too rapid of a rate of change in voltage), or at the very least do incremental damage to the silicon substrate of the transistor. The drive doesn't really "care", but the owner will when the repair and downtime bill comes in."
    http://www.mikeholt.com/code_forum/showthread.php?t=79477&page=2
    "This motor, as it becomes available, would be the preferred choice for 480V and 575V IGBT drive systems having 2 pu reflected wave motor voltages of 1300 Vpk and 1600 Vpk respectively." See Riding the Reflective Wave at http://www.google.com/search?q=voltage spike vfd&hl=en&lr=&start=50&sa=N

    "VFD motors are designed for variable speed. Motors that are not will probably not suffer from imbalance. There may be other electrical issues, but they are balanced. There may be resonances, but balanced is balanced."
    You are correct about it being resonance and not balance but the motor does not know the difference because it is still vibrating like crazy. Motors specifically made to work with VFD are standard induction motors that have been modified with 2,000 volt insulation, insulated bearings, shaft grounding capability, etc. to try and offset the destructive parameters of the VFD.
    "The motor used in a VFD system is usually a standard squirrel cage three phase induction motor." http://en.wikipedia.org/wiki/Variable_Frequency_Drive

    "Properly designed systems do not put noise back on the power line. A VFD drive generally first converts line voltage to a DC supply using the same type of switching power supplies mentioned by Bob NH. This power supply effectively decouples the VFD signal from the line. A DC supply meeting current standards also corrects power factor to the line."
    "When these diode blocks conduct power to charge the DC bus of the drive they cause an imbalance in the current waveform that causes an imbalance in the voltage waveform. This imbalance (disturbance) appears at the input of the drive and is reflected into the AC line feeding the drive." http://pumpmaster.aidusa.com/html/faq.htm

    "Yes a square wave generates all harmonics of the fundamental frequency. No it does not get back to the line in a properly designed system. In a poorly designed system it mostly annoys things like X10 remote controls which operate at very low frequencies. The harmonics may also annoy an AM radio with little line isolation or via radiation for short ranges. As noted, so will a PC or flourescent light. I have some lights I bought from HD and they ruin my FM radio reception. They have lousy line isolation and the tubes radiate. Local radiation is short range and since the wavelength of the frequencies involved in an VFD are very long the equipment is not a very efficient antenna; hence minimal ambient radiation. A switching power supply (which also generates square waves) can have switching frequencies into the megahertz range and are much more likely to be a problem."
    "This imbalance (disturbance) appears at the input of the drive and is reflected into the AC line feeding the drive." http://pumpmaster.aidusa.com/html/faq.htm

    "I am also not sure why a VFD drive would provide less overall efficiency when matched to the load characteristics than any other possible solution. Certainly not pumping at max capacity and throwing away some large fraction of the energy applied via a bypass back to the source. That is not why VFD drives are very popular industrial solution as a energy saving device. A VFD pump coupled with the appropriate sensor should provide a very effective pumping solution without wasted energy."
    "A VFD does provide efficient control for pumping applications. There is just such little difference in constant pressure systems in using a drive and restricting the flow of a pump with a valve, (not dumping excess flow with a valve) that it never pays back the added expense."
    http://www.cyclestopvalves.com/comparisons_13.html

    "I do not believe that the concept of "carrier frequency" applies to a VFD controller."
    "The switching rate of the output transistors is controlled by the VFD's Carrier Frequency parameter. Increasing the Carrier Frequency will reduce the audible noise from the motor."
    http://www.control.com/1026203703/index_html
    Last edited: Jun 5, 2007
  12. speedbump

    speedbump Previous member

    Messages:
    4,540
    Location:
    Riverview, Fl.
    Correct me if I'm wrong. Single phase motors cannot be used as VFD motors. The motors must be three phase!

    True °

    False °

    I can visualize what would happen to a capacitor start motor constantly changing speeds.
  13. valveman

    valveman Moderator Staff Member

    Messages:
    4,369
    Location:
    Lubbock, Texas
    Valveman

    Franklin makes a Mono Drive that runs single phase sub motors up to 1 HP. All the same control problems of the 3 phase drives and a couple extra. Uses a go / no go switch instead of a pressure transducer. I am a show me kind of guy, don't take what I read on the Internet as gospel. This is one of several different drives I purchased and have working in my test pit. Can show you what it does and doesn't do if you ever want to come see, along with several other drives that are supposed to be "state of the art".
  14. speedbump

    speedbump Previous member

    Messages:
    4,540
    Location:
    Riverview, Fl.
    So I would assume these are two wire motors. What happens to the biac switch with all that switching on and off. Or do they remove it before using it on one of these Mono Drives?

    The only Variable Speed Pump I have any experience with is the Myers GEM. It was a 1/2hp and they said the little 1 gallon bladder tank would work fine with it. Later they came out with the statement that we should consider using the 42 gallon bladder tank instead.

    This motor did not change speed as near as I could tell, it just switched on and off real fast to keep up with demand. You would think that alone would damage a motor and pump in a hurry.

    Next thing they did was get out of the Variable Speed Pump business. That was quite a few years ago.

    Just like Ozone. I tried it, didn't like the quality of the units that were available. After testing them and finding out they wouldn't last a year I forgot about them.
  15. bigballer

    bigballer New Member

    Messages:
    9
    Location:
    Seattle, WA
    wow i really got more then i bargained for when i started this thread. i didn't realize there were such vocal opponents of the vfd systems. i will take this information and present it to my pump contractor who is suggesting this setup. i would like to know his opinions since he seems to have reasonable experience with many different types of systems and has been doing so since since 1960.

    thanks for your opinions on this.

    cheers,
    bigballer
  16. valveman

    valveman Moderator Staff Member

    Messages:
    4,369
    Location:
    Lubbock, Texas
    Valveman

    Ask him what is the oldest one of these (exactly same with no changes) units he has working and does he have one at his house. Some pump installers like to sell these units because they make more money and the units don't last as long as normal pumps. If he hasn't had one working for atleast 5 years, you are another test subject. Manufacturers are pushing their installers to use these units because it goes right along with their planned obsolesence. Just yesterday an installer who sells larger drives told me that he loves to sell drives because he makes 20 or 30,000 dollars a pop and locks himself into a lifetime service contract because no one else but him knows how to make it work. That will work until his customers figure out that they could have had better performance using a valve instead of a drive for pennies on the dollar, and the valve would have been simple, dependable, and long lasting.
  17. bigballer

    bigballer New Member

    Messages:
    9
    Location:
    Seattle, WA
    please send me CSV pricing for my system - 20gpm flow, 130ft head, 350ft of 1" line to pressure tank, 4.5 gallone tank.

    cheers,
    bigballer
  18. speedbump

    speedbump Previous member

    Messages:
    4,540
    Location:
    Riverview, Fl.
    CSV Pricing
    You will need the CSV1. If your hanging it in the well, you will need the CSC1 coupling to strengthen the valve to hold the weight of the pump.

    bob...
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