EC motors have been around for decades, but they have not historically seen widespread adoption in pump systems due to cost and compatibility issues. But these conditions are changing fast. The industry is at a point where manufacturing advances and market demands are converging to make EC motors a practical soluton.
EC motors and conventional induction motors have different fundamental operating principles. An induction motor rotates by relying on the interaction between the rotating magnetic fields produced by the stator and the “induced” electric fields in the rotor. In an EC motor, the electric current switches or “commutates” between phases in the stator using digital switching circuits, and the rotor is permanently magnetic.
EC motors are, in principle, the same as brushless direct current (BLDC) motors and permanent magnet synchronous motors (PMSMs). Because there is no current or heat generated in the rotors, EC motors are generally around 25% more efficient, the thermal management is simplified and reliability is improved. Their lower inductance also results in a 10% improvement in power factor, meaning less energy is wasted in a building’s electrical lines. They are able to achieve 25% higher torque densities and flatter efficiency curves, can maintain constant speed with varying loads and often come with integrated drives that provide flexible control strategies.
Demystifying EC Motors
Despite their advantages, EC motors suffer from some perception problems from consumers, particularly around their cost, complexity, integration challenges and supply chain risks. However, these shortcomings are often manageable, and there is still usually a net positive in adopting this technology.
Firstly, and probably most importantly, there is the sticker shock of seeing the upfront price of an EC motor. While it is true that an “equivalent” EC motor can cost upward of 50% more than an induction motor, this increase in capital expenditure (capex) is often substantially or completely offset by the savings in operating expense (opex). Not only would an EC motor be more efficient in general and therefore reduce energy costs, but optimizing a motors control strategy around a specific duty cycle could unlock even more savings.
Furthermore, if precise speed control is required, motors with an integrated drive can reduce the bill of materials (BOM) and maintenance costs of an auxiliary variable frequency drive (VFD). EC motors themselves also offer high reliability, further lowering general maintenance costs. A widely accepted engineering principle states that for every 18 F (10 C) increase in winding temperature, the thermal life of the motor’s insulation system is reduced by half. Any applications that require service factors greater than 1.0 can see great benefit from switching to EC motors, which can operate much cooler.
Finally, the cost of the materials and electronic components in an EC motor is shrinking. Advances in motor topology and material science are still pushing the cost of EC motors down, while traditional induction motors have mostly levelized, so the situation is trending in EC motors’ favor. When accounting for all these hidden costs, the true lifetime cost of an EC motor is substantially lower than that of an induction motor.
The next likely concern is around the complexity of EC motors, particularly around the integrated electronics that give the motors their flexibility. These electronics enable advanced control strategies, but if they fail, repairs can be more specialized and costly compared to mechanical failures in traditional motors. With advances in power electronics and control systems, however, this failure mode is much less likely than a bearing or winding failure in the motor. A well-designed EC drive is often designed to last longer than the motor itself. In the case of an unexpected failure or external damage to the electronics, many EC motors can operate with standard, off-the-shelf PMSM-compatible VFDs.
Some suppliers are concerned with the integration challenges associated with switching to EC motors, believing they are not available in standard National Electrical Manufacturers Association (NEMA) frame sizes. This is no longer the case either. Contemporary EC motors are often fully compatible with NEMA frame sizes and mounting dimensions, eliminating costly redesigns and integration headaches.
Finally, users are often concerned about supply chain risks around EC motors—particularly the continuing trade tensions surrounding rare-earth magnets. In April 2024, China, the supplier of around 90% of the world’s rare-earth elements, imposed severe export restrictions on rare-earth magnets. This geopolitical move has disrupted global supply and raised costs, renewing concerns for industries reliant on these materials.
In response, many EC motor manufacturers have started to shift focus to ferrite magnets, which are both 90% cheaper and globally abundant. While ferrite magnets are weaker than neodymium magnets, new motor topologies have enabled EC motors using ferrites to achieve IE5 “ultra-premium” efficiency ratings, while still being more compact than equivalent induction motors.
The Evolving Demand for EC Motors
So why are EC motors suddenly a viable option? What has taken them from a niche “efficiency upgrade” often overlooked by the industry to a technology at the center of a serious surge in adoption? There are three key factors that explain why EC motors are finally having their breakout moment: an increasing demand for efficiency, the increasing number of OEMs creating more innovative designs and the increasing demand for enhanced control functionality.
In 2023, both the U.S. Department of Energy (DOE) and the European Union (EU) passed new standards to increase the minimum motor efficiency requirements from IE3 to IE4 for a wide range of output powers. These requirements will soon exceed what is possible with induction motors, driving more demand towards EC motors. In 2024, the DOE also proposed new, more stringent standards for heating, ventilation and air conditioning (HVAC) and pump systems as a whole, meaning either the motor or the end effectors must get more efficient.
On the other end of the equation, according to the U.S. Energy Information Administration, retail electricity costs have outpaced inflation since 2022, with anywhere from an 8%-25% increase between 2022 and 2025. This trend is expected to continue, with areas with higher costs seeing the greatest inflation. This combination of more stringent regulatory requirements with rising energy costs has greatly increased the impetus to switch to EC motors.
Perhaps anticipating this demand, more and more manufacturers have recently entered or emerged in the EC motor space. This has led to more innovation in the form of even more efficient, more compact and more reliable designs. For example, in the late 2010s, the industry saw the emergence of printed circuit board (PCB)-based EC motors, and just in the past two years, newer technologies with ferrite magnets have entered the scene. This increasingly competitive market space will drive the price of EC motors down further, reducing the barrier of entry for users.
Finally, there is increasing demand for advanced onboard control functionality of motors in the pump space. This could be for more precise torque or speed control, better load-balancing across distributed systems with transient spikes or integration with smart monitoring and preventive maintenance systems.
These functions are not merely nice-to-haves but can generate real value for users. Sometimes off-the-shelf VFDs do not, or cannot, offer some of these features with induction motors. There are fewer limitations with the onboard controllers on EC units, and manufacturers tend to include these advanced functions as part of their value-add.
EC motors are not a futuristic technology for the few. They are a well-understood, readily available and timely solution for today’s industry’s needs.
