The introduction of variable frequency drives (VFDs) was transformational for electrical motor assemblies, delivering unmatched efficiency and cost savings. However, they also came with challenges. The high-frequency electrical noise generated by a VFD can lead to motor bearing damage and electromagnetic interference (EMI). While mechanical solutions exist to mitigate these issues, they are prone to wear and tear, which require regular maintenance to stay effective.

As VFD technology evolves with the new SiC and GaN technology, which offer higher frequencies and better efficiencies, these traditional mechanical solutions of mitigating high-frequency electrical noise will no longer remain effective.

MH&W, the leading US distributor of cutting-edge Nanocrystalline magnetic materials in the U.S., Canada, Mexico and the Caribbean, introduces the answer to this dilemma. Its offerings: German designed CoolBlue® & NaLA® filter cores manufactured by MAGNETEC and MH&W’s own Filter Kits, solve the electrical noise conundrum. They act as common mode chokes (CMC) and differential mode chokes (DMC), absorbing VFD’s electrical noise through induction and dissipating it as thermal energy. These innovative nanocrystalline-based products also have the added advantage of EMI shielding, enabling them to protect sensitive components and improve overall system reliability (RMC).

More importantly, these products require no maintenance since they eliminate components like mechanical grounding rings or brushes that wear out over time.

“The industry has been reliant on mechanical solutions to solve an electrical problem. We are rewriting that paradigm by introducing an electrical solution for an electrical problem,” says Dave Rollins, Executive Manager, Engineering at MH&W.

MH&W collaborates closely with its manufacturing partners, prioritizing engineering solutions over cost concerns to deliver reliable, knowledge-based innovations.

The CoolBlue® Advantage

Magntec’s CoolBlue® & NaLA® cores along with MH&W’s Filter Kits feature toroidal/racetrack cores made of nanocrystalline material, which features superior soft magnetic properties that surpass permalloys, ferrites and even amorphous cobalt-based alloys. The company calculates the exact number of cores required to effectively absorb and dissipate the noise while minimizing the heating to ensure optimal working conditions for the motors.

  • We welcome any engineer or technician to put our product to the test. This is new and the skepticism is understandable, but We’re confident in what we offer


The products are a practical choice for both new and retrofit applications as they are designed to minimize downtime during installation and do not need complex modifications. Once installed, these filters provide lifetime protection, eliminating bearing failure and EMI-related issues.

Science-backed Brilliance

Unlike conventional solutions emphasizing voltage reduction, Magntec’s CoolBlue® & NaLA® cores and MH&W’s Filter Kits directly address the damaging currents. This foundation of scientific ingenuity is what makes MH&W’s solutions exceptional.

“Our products don’t affect the voltage part of the power equation. The damage to motor bearings is 100 percent caused by the current. Our solution is built to minimize any wearing,” says Ori Kasneci, National Sales Manager, Filter Division.

To put things into perspective, these currents can reach levels of 50+ amps, an extraordinary amount of current considering their frequencies. The typical frequency of damaging currents ranges from 100KHz to 5MHz and are invisible to standard 60Hz clamp-on probes. Measuring them requires a more specialized instrument called a Rogowski coil along with at least a 100MHz oscilloscope. Without proper measuring tools, these currents remain hidden, allowing damage to continue unchecked.

MH&W has taken a proactive approach to spread awareness regarding this phenomenon by conducting live demonstrations, offering free trial programs and publishing technical research.

“We welcome any engineer or technician to put our product to the test. This is new and the skepticism is understandable, but we’re confident in what we offer,” says Ulrich Gernhardt, president.

MH&W backs up its confidence by starting a program that allows engineers to test the cores and kits for six months, completely free of charge. If the solution does not meet expectations, it can be returned at no cost, underscoring the company’s commitment to proving the products’ value.

Real-world Impact

MH&W’s filtering solutions are in use across multiple industries and by some of the most recognizable brands in the world, with many calling it “pixy dust” for its effectiveness in addressing fluting and pitting of motor bearings. A notable example is a world-class manufacturer of air-conditioning units. This OEM studied the products for numerous years before integrating them into their products.

Today, all these customers’ industrial chillers use MH&W’s solutions, taking advantage of their extended life and zero maintenance requirements. Many other companies, including global EV manufacturers, have also put their confidence in CoolBlue® & NaLA® cores and MH&W’s Filter Kits.

But noise filtration’s applications don’t stop here. From data centers that rely on massive cooling fans to aquariums using powerful pumps and water treatment plants, modern technology is deeply dependent on VFDs. Even iconic skyscrapers like One World Trade Center use elevators protected by this technology, while hospitals rely on fan walls to keep operating rooms at precise temperatures. Any industry that uses VFD-driven motors stands to gain from MH&W’s supplied advanced noise-filtering cores, which help prevent costly breakdowns and ensure smooth, continuous operation.

As the reputation for its products continues to rise, MH&W aims to establish CoolBlue® & NaLA® as a standard feature in every VFD-driven motor. The company is actively expanding their resell network to ensure around-the-clock product availability and technical support across diverse industries.

Redefining Motor Protection

In an industry where downtime translates directly to financial losses, MH&W’s promise is clear, “no time for downtime.” Backed by a lifetime motor protection guarantee, CoolBlue® & NaLA® filters provide the ultimate solution to one of the most persistent challenges in modern motor-driven systems.

By continuing to challenge industry misconceptions and demonstrate the superior performance of CoolBlue® & NaLA® technology, MH&W is poised to reshape the landscape of motor protection. Today, with approximately 50 percent of the world’s electrical power being consumed by motors and nearly 16 percent of those motors now running on VFDs, the importance of efficient motor operation cannot be overstated. The electrical noise challenge grows with the adoption of faster and more efficient switching technologies and the demand for reliable, maintenance-free solutions will only increase. MH&W remains committed to keeping pace with the evolving landscape, delivering innovative, engineering-driven solutions that ensure reliability, efficiency and long-term performance.