Grundfos Magna3 Energy Saving Circulator Pump
Approximately 50 percent of the energy savings derives from the circulator’s permanent magnet motor design, rather than the induction motor design used by conventional pumps. Even if you ran the MAGNA3 as a “dumb” pump — setting it at a constant, maximum speed without any modulation — it would still cut energy consumption in half versus a conventional pump, while delivering a starting torque four times higher than a standard induction motor. The use of AUTOADAPT should reduce energy usage by another 25 to 35 percent. As a result, an end user can expect to cut energy consumption by up to 85 percent — maybe more, depending on the application and whether the pumps being replaced were sized properly.
What makes MAGNA3 a “smart pump” and how does it differ from other circulators on the market?
In a word, AUTOADAPT. MAGNA3 offers much more than multiple pump speeds to match varying system loads. Grundfos is the only manufacturer to offer an ECM circulator that uses an integrated logic algorithm to “learn” the varying energy-usage patterns of an application over time, enabling the software to automatically determine the lowest possible operating‐efficiency point to meet ever-changing demand. By continuously fine‐tuning power consumption and flow rates to meet the dynamic needs of the system, this AUTOADAPT function saves both energy and money.
What are the most notable upgrades in the new Grunfos MAGNA3?
With MAGNA3, Grundfos has worked to make a smart pump even smarter with the following enhancements:
- FlowADAPT: The new MAGNA3 allows the installer set a maximum flow rate that the pump will never exceed, eliminating the need for additional valving to restrict the flow. This option is available whether the installer opts to use AUTOADAPT or either of the MAGNA3’s other two modes: constant pressure and proportionate pressure. (The latter may be preferable, depending on whether head-loss in greater in the pipeline or in the zone valves.) With AUTOADAPT, the fixed flow rate becomes simply another parameter the system “learns” on its way to minimizing energy usage.
- Carbon fiber reinforced composite rotor caN: The function of the rotor can is to seal fluid from the stator motor. In the current MAGNA, the can is made of stainless steel, but we moved to the carbon-fiber material because it permits better transmission of the magnetic field through the can, raising overall pump efficiency.
- Differential pressure sensor: The existing MAGNA has no pressure sensors. Performance is entirely based on power consumption and speed, and then programmed into the pump’s characteristics. With the new MAGNA3, we integrated a patented differential pressure sensor right into the pump housing. In doing so, we opened up the hydraulic design, resulting in increased efficiency for the hydraulics, as well as the motor.
- Constant temperature mode: A system sensor allows the MAGNA3 to monitor flow temperature constantly. A circulator placed in the return line in a domestic hot water system can be programmed to maintain a constant temperature. This, in turn, enables the pump to slow down when hot water demand is low or nonexistent — a big energy- and money-saver in certain commercial applications, such as schools and hotels, whose need for hot water varies greatly throughout the day.
- On-pump, TFT display screen: This new screen provides clear, easily readable text right on the pump; the installer and end user can even see the pump curve. Thanks to this new technology, the installer can request “assisted setup” at the time of commissioning, while a service technician can use the same feature to troubleshoot problems. The screen will “step” the installer or technician through a series of questions and procedures, so they accomplish whatever task they must perform quickly and easily. This is a major improvement over conventional pump interfaces, which typically display codes that require the user to memorize or look up in a separate manual. With the MAGNA3, it’s all on the screen.
Rotating power head: There’s one more important, but relatively simple change that has elicited excellent feedback from installers who have tested it: On a conventional circulator, rotating the power head necessitates