How CoolBLUE® & NaLa® Deliver Unmatched Bearing Longevity
Variable frequency drives (VFDs) have revolutionized industrial motor control, delivering energy efficiency, precise speed regulation, and reduced mechanical stress across countless applications—from HVAC systems and pumps to renewable energy inverters and manufacturing lines. Yet this technology comes with a well-known hidden cost: high-frequency currents generated by pulse-width modulation (PWM) that damage motor bearings through electrical discharge machining (EDM), fluting, frosting, and premature lubrication breakdown.
Traditional mitigation methods—such as shaft grounding brushes, insulated bearings, or older ferrite-based chokes—often fall short. They require ongoing maintenance, introduce wear, or simply cannot handle the broadband noise effectively. Enter the real innovation: Magnetec’s NANOPERM® nanocrystalline material, exclusively available in North America through MH&W International Corp. via our CoolBLUE® common-mode inductive absorbers and NaLa® differential-mode line absorbers.
Why Nanocrystalline Cores Represent a True Leap Forward
NANOPERM® nanocrystalline cores are not just another magnetic material—they’re a fundamentally superior solution engineered for modern power electronics. Compared to conventional high-permeability ferrites (10K or 15K materials), nanocrystalline offers:
- Up to 10× higher permeability — delivering dramatically higher impedance across a broad frequency range (especially critical for VFD-induced common-mode currents).
- Higher saturation flux density (Bsat) — allowing smaller, lighter cores to handle the same currents without saturation.
- Extended operating temperature — up to 180°C, far exceeding most ferrite limits.
- Superior broadband performance — excellent attenuation from DC up to 100 MHz, exactly where VFD noise lives.
When formed into CoolBLUE® cores, this material acts as a highly effective common-mode choke. Installed on the load side of the VFD (ideally inside the drive cabinet), the cores absorb destructive high-frequency currents before they reach the motor bearings. The result? Bearing currents are slashed—often from tens of amps down to just a few—preventing EDM pitting and dramatically extending motor life.
For applications demanding the highest reliability (motors ≤10 HP or systems with long cable runs), NaLa® differential-mode absorbers provide the perfect complement. Placed around each individual phase conductor, NaLa® further reduces peak currents and slows dv/dt, adding an extra layer of protection that traditional single-choke solutions cannot match.
Real-World Impact and Installation Simplicity
MH&W’s CoolBLUE® and NaLa® solutions are already proven in thousands of installations worldwide:
- OEM HVAC equipment
- Paper mills and automotive plants
- Hospitals, commercial buildings, and renewable energy (wind/solar) systems
- All types of pumps, fans, and precision servo drives
Installation is tool-free and maintenance-free: simply slip the oval or round cores over the motor cables (multiple turns where specified for smaller motors). No rust, no brushes to replace, no grease or dirt issues. Unlike mechanical shaft solutions, the cores last the lifetime of the system.
Selection is straightforward using MH&W’s published VFD application guides (based on horsepower and cable length). Our engineering team is always available to review your exact application and recommend the optimal core combination.
