How to Prevent Electrical Bearing Damage

Posted on August 13, 2019

Exposing a bearing to an electric current can cause electrical bearing damage. The damage manifests as pits and grooves on the bearings' surface create an uneven surface texture causing additional noise, vibration, and (eventually) complete failure. These outcomes can be costly, often leading to unnecessary downtime and expensive repairs or upgrades.

Although not all bearings are damaged by an electrical current and not all circuits cause bearing damage, there are two situations in which the problem typically occurs: when equipment is grounded incorrectly or when bearings are used in AC/DC motors with variable frequency drives (VFDs).

In the case of improper grounding, the current produced often finds and discharges along the path of least resistance to the ground, which is typically through exposed bearings. With VFDs, the problem is similar—voltage builds up on the motor shaft and is repeatedly discharged into the bearings. This discharge of current is what leads to the formation of fluting or pitting patterns within the bearing, which, in turn, cause equipment malfunction.

One solution to electrical bearing damage is replacing standard bearings with ceramic hybrid bearings. These devices offer greater electrical and temperature insulation properties, which prevents current discharge and makes them ideal for situations involving VFDs or other grounded motors.

What Are Ceramic Hybrid Ball Bearings?

CERAMIC-1Ceramic hybrid bearings consist of ceramic rolling balls and an inner and outer steel race. The design and construction of these bearings are ideally suited for hybrid capacities and for preventing electrical damage. Ceramic bearings provide a level of insulation that eliminates electric arcing and fluting. They also feature double shielding and non-conductive properties and low temperature rise under extreme operating conditions.

Nachi ceramic hybrid ball bearings, for example, are one of the most durable replacements for traditional steel bearings. They are dimensionally interchangeable with most bearings, which eliminates the need for special modifications during the installation process, facilitates the replacement process, and makes them a more cost-effective replacement option.

Additional Benefits of Ceramic Hybrid Ball Bearings

Apart from their insulating properties, there are many other advantages to switching to ceramic hybrid ball bearings, including:

  • Lightweight construction
  • Safer operation in extreme conditions
  • A wider range of speed capabilities
  • Operation with a very low coefficient of friction, allowing for faster equipment rotation and higher power output
  • Longer life spans and lower risk of premature failure than other types of bearings, making them cost-efficient over their longer working lives
  • Elimination of the use of heavy lubricants such as oil or grease, which prevents the risk of contamination and decreases environmental impact

These benefits make hybrid bearings an ideal choice in applications where extra bearing protection is necessary, such as:

  • Food processing
  • Food packaging
  • Motors with VFD
  • Air Handling
  • Chillers
  • HVAC Units
  • Compressors
  • Conveyors
  • Pump Motors
  • Elevators
  • Refrigeration
  • Fans
  • Data Centers
  • Generators

Safeguard Your Bearings With Emerson Bearing


Bearings can be damaged by electrical current, as well as many other environmental and operational factors. Understanding these factors and the risks they possess is the best way to prevent costly repairs, downtime, or operator injuries associated with damaged or failed components.

Our eBook, Increase Bearing Service Life and Optimize Performance, educates you on the most critical aspects of damage prevention, teaches you how and why bearings become damaged, and outlines what you can do to preserve the working life of these essential parts. To learn how to maximize efficiency and safeguard your equipment investments, download Increase Bearing Service Life and Optimize Performance today.

To learn more about integrating our long-lasting bearing solutions into your facility, contact our team today.



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