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Understanding the Taco 007e

abdunbar
abdunbar Member Posts: 1
edited August 2020 in THE MAIN WALL

Based upon Uponor's charts, it looks like for 100% water circulating at around 110 degrees F, 10 foot of head will circulate about 1 gallon per minute through 250 feet of 1/2 inch pex at about 2 feet per second. Not asking if this is a good idea just want to understand the 007e pump. So with just one circuit of 250 feet of 1/2 inch pex hooked up to the 007e, it looks like it will push up to its 10 foot maximum and circulate that water as stated above at about a gallon per minute. Is that right? Now if another circuit is added, the pump will circulate 2 gallons per minute total and so on as you add circuits until you add the ninth 250 foot circuit and now the pump will not circulate the same amount of water but slightly less because it will not make the full 10 foot head at this flow. It looks like that at 10 circuits of 250 feet, there is just 8 foot of head available. Going back to Uponor's chart, 8 foot of head divided by 250 foot of 1/2 inch pex is .032 foot of head per foot and at 110 degrees F, that would be about 8.8 gpm moving at about 1.6 feet per second. I understand that this is an approximation, I am guessing an exact interpolation would be a calculus problem just want to know if this is a correct understanding of how the 007e operates?

Assuming this is correct, how does the pump sense the increased demand?

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 22,877
    Not a calculus problem at all -- just the way pumps operate. First, step back and look at the basic 007 (without the e). This is a bog standard centrifugal pump, and is notable for (and useful because of!) a remarkably flat pump characteristic at constant speed (60 hz). Now what Taco has done is swap out the older AC motor (which will run until Doomsday, but at only one speed) for a variable speed, electronically controlled motor (hence ECM).

    The pump's controls sense the flow or pressure difference, and vary the speed of the motor to reach the desired flow (there are other conditions which can be sensed, such as delta P or delta T). The 8.8 gpm at 10 feet of head is the maximum the pump with the original motor can reach. Below that head, the old pump's flow was greater; above that head, less -- the difference is that the 007e's electronics give a constant head (in normal mode) at any flow up to 8.8 gallons per minute.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • hot_rod
    hot_rod Member Posts: 21,793
    I think 1 gpm in a 250' loop of 1/2 pex @120F would be around 8' head?
    1 gpm seems a bit high, the RadPad shows a suggested max. of .6 gpm in a 300' loop of 1/2".
    Unless the 1 gpm is just for an example?

    This journal take you through the steps of developing a system curve, overlay on the pump curve.
    Also how the various delta p functions work.

    https://www.caleffi.com/sites/default/files/coll_attach_file/idronics_16_na_0.pdf
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Joe Mattiello
    Joe Mattiello Member Posts: 703
    Hi there
    you're right, the 007, and 007e are fundamentally variable flow, net flow is dictated by the system resistance. first step in sizing the pump, is knowing the amount of BTU's that have to get delivered to load. Next the piping has to be sized adequately to accommodate the flow rate required based on Load. quick rule of thumb for a 20 degree delta T, is approximately 1 GPM per 10,000 BTUs. the resistance through the selected length of pipe and diameter will give you the two variables necessary (Flow & Head), to size a pump. Here's where your analysis compares, the flow rate through 250 lineal feet of 1/2" pipe is the pressure drop the pump is pumping against and dictates where the pump operates on it's curve. This is true with both types as Jamie Hall so eloquently explains in this tread. There's a great video on tacocomfort.com called understanding ECM circulators. For your convenience, I provided a link.
    http://www.tacocomfort.com/products/variable_speed_products/007e/index.html
    great way to understand why electronically commputated motors, ECM are more efficient, in comparison to PSC type AC motors.
    Please reach out to Taco Tech support at 401-942-8000 is you have additional questions regarding any Taco products.
    Joe Mattiello
    N. E. Regional Manger, Commercial Products
    Taco Comfort Solutions
    HVACNUTfenkel
  • Robert O'Brien
    Robert O'Brien Member Posts: 3,537
    This weeks Taco After Dark covers this topic
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • Robert_25
    Robert_25 Member Posts: 527
    I am considering a Taco 007E to be paired with some zone valves in my home. I watched some videos explaining the features of the 007E, and one person said that it can sense when there is no load and shuts off. Does that mean the 007E can be powered all the time, or does it need to be wired with a relay like a traditional circulator?
  • SteveSan
    SteveSan Member Posts: 231
    edited September 2020
    Hi Robert, attach is the wiring diagram off the IOM showing you can hard wire the Taco 007e or you can wire through one of our controls ZVC or SR controls. If you have any questions please call into Taco Tech Support Mon-Fri 8am-5pm EST. 401-942-8000

    007E.png 108.7K