Electrical Fluting: What It Is & How to Prevent It

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Electrical fluting can challenge industrial technicians tasked with maintaining and repairing electric motors. Left unchecked, extraneous electrical charges can gradually degrade internal motor components, rendering the motors inoperable.

Traditional routes to address electrical fluting involve constant inspection and maintenance, costing the owner valuable time and money. Advanced nanotechnology now allows owners of electric motors to prevent electrical fluting before it happens.

What is Electrical Fluting?

Electrical fluting is a form of electrical erosion where electrical discharge strips metal surfaces and erodes the material. Electrical fluting presents as a series of ridges or “flutes” that appear along bearing raceways, especially in motors equipped with variable frequency drives (VFDs).

Voltage buildup along motor shafts always seeks the path of least resistance, often grounding through the motor’s bearings via high-voltage arcing. Unintended bearing discharge leads to electrical erosion and scarring along the bearing, raceway, or roller surfaces.

Due to high switching frequencies, VFDs are notorious for producing higher levels of electrical buildup. Taking extra precautions is necessary to protect motors and extend service life.

Signs of Electrical Fluting

When electrical fluting damages bearings and other rolling components, it can lead to major malfunctions or even inoperability. The following can indicate the presence of electrical fluting:

• Loud, unexplained motor noises
• Washboard-like ridges along bearing raceways (fluting)
• Irregular sheen on bearings, raceways, or rollers (frosting)
• Pits, cracks, and discolorations

Depending on the component type and extent of the damage, you may notice differing symptoms. It is important to examine the component thoroughly and confirm the exact cause.

The Solution: Nanocrystalline Technology

Nanocrystalline technology is an innovative electrical fluting solution that addresses the root cause of damage for maximum bearing protection. Magnetec’s CoolBLUE^® incorporates several advanced design features, including:

• System-Wide Protection. Using inductive absorbers, CoolBLUE^® protects all motor components from damage caused by high-frequency common mode currents.
• Advanced Electrical Absorption. The absorbers are made from nanocrystalline materials that “choke” and absorb stray currents produced by the VFD’s insulated gate bipolar transistor (IGBT) or Silicon Carbide (SiC). Doing so lowers current potential along the motor shaft and protects bearing components from electrical erosion.
• Enhanced With Nanotechnology. Magnetec’s NaLA^® nanocrystalline line absorbers reduce peak voltage and electrical noise for added protection, while Magnetec’s Nanoperm^® material derives greater performance and efficiency with fewer cores.
• Comprehensive Coverage. The user can configure CoolBLUE^® as a common mode choke around all phases and place NaLA^® differential mode chokes around individual cables to protect the entire motor system.
• Major Reduction in Common Mode Current. CoolBLUE^® and NaLA^® helps motors achieve at least a 65% reduction in common mode current to maintain safe operating limits.
• Superior Bearing Protection. Where shaft grounding devices only mitigate damage to the motor, CoolBLUE^® stops stray VFD currents from entering the entire motor systems in the first place.
• Multifaceted and Extended Protection. CoolBLUE^® resolves numerous system errors by reducing bearing damage, motor or winding overheating, insulation wear, and electronic interference.

Shaft grounding and other mechanical solutions require ongoing maintenance and merely reduce the symptoms of EMD and VFD discharge. CoolBLUE^® achieves a multifaceted, maintenance-free solution that protects the longevity and performance of electric motors.

Permanent Motor System Protection With MH&W’s Filter Solutions

Understanding the causes and ramifications of electrical fluting is essential to protect motors and their critical components while minimizing maintenance costs.

MH&W leverages some of the most innovative nanocrystalline materials and non-mechanical solutions to prevent electrical erosion, pitting, and frosting on bearing components. To learn more about the revolutionary technology behind CoolBLUE^®, contact us or request a quote today.