Every week a question comes in to R. L. Deppmann about the minimum flow rate through pumps. In hydronic heating and cooling systems, it is …
B & G ecocirc e3 with ECM Technology (Electronically Commutated Motor)
Bell and Gossett’s ecocirc pumps were introduced over the last few weeks. We promised to explain how the ECM technology provides more efficiency than standard induction motors. Let’s talk about the difference between a standard induction motor vs. a permanent magnet motor. With an induction motor, stator windings are arranged around the rotor so that when they’re energized, they create a rotating magnetic field.
Let us take some time to answer YOUR questions…
We received a great deal of questions from last week’s Monday Morning Minutes on the Bell and Gossett Ecocirc domestic water inline pump. Two of the most asked questions were; Why is more reliable? And How does it save energy? The ECOCIRC is more reliable because there are less moving parts. Here is a brief description.
NEW PRODUCT: Energy Efficient Ecocirc 19-14 Auto & Vario Heat Circulators
We are very pleased to announce the addition of the new ecocirc 19-14 heating circulators to our line of energy efficient products. As with the rest of the ecocirc line, this new offering also utilizes Electronically Commutated/Permanent Magnet motors, which by design are more efficient than permanent split capacitor induction motors. This technology also offers more flexibility than standard motors allowing us to add features via software logic rather than hardware that would otherwise add cost.
Centrifugal Pumps – “Clipping the Tips”
R. L. Deppmann regularly receives questions when a field problem pops up. Here is an example call from an industrial user with a pump issue. There is an existing Bell and Gossett model 1510-5BC with a capacity of 1000 GPM at 60 foot head using a 25 HP, 1750 RPM motor and a 9” cut impeller.
Centrifugal Pump Selection Specifying Future Conditions
In the last R. L. Deppmann Monday Morning Minutes, we suggested a specification that would allow a future impeller change as a means of adding some safety factor to the pump provided on your project. What happens if you want to select a pump with a present and future condition? Here is a good pump selection for a capacity of 2700 GPM at 100 foot head using a 100 HP 1750 RPM motor.
Constant Speed Pumps and Maximum Impeller Concerns
How many times have you, as an engineer, looked at a number of curves and passed up a few because you did not like something about the selection on that curve? In the last R. L. Deppmann Monday Morning Minute we looked at end of curve selections. Today we examine pump selections near the top of the…
Centrifugal Pump Selection Maximum Point on the Curve
How many times have you, as an engineer, looked at a number of curves and passed up a few because you did not like something about the selection point on that curve? In the December 6, 2010 R. L. Deppmann Monday Morning Minutes, we look at how to specify and schedule pumps to limit the bidders to to specific pump curve characteristics.
Pump Selection – Flat vs. Steep Curves
An engineer in Michigan called about a large project with several pumps being selected in parallel for a plant chilled water system. He commented that the Bell and Gossett pump curves are flat vs. processing pumps which often times are steep. His question was, “Why are B&G curves so flat?” I’ve not heard this comment for many years. What did he mean? The term steep curve comes from the process industry. This old term refers to a large change in pump head with a small change in flow rate.
Large Centrifugal Inline Pump Installation
In our last Monday Morning Minute, we suggested using the Base Mounted Bell and Gossett series 1510 series end suction or VSX series double suction pumps when the design capacity requires over 10 HP. We do occasionally see our series 80 and series 80-SC inline pumps specified in applications up to 100 HP. Often the reason used for this application is limited floor space. Today let’s examine floor space required by these pumps.