When a bearing is exposed to an electric current, it can cause electrical bearing damage, which manifests as pits and grooves on the bearings’ surface. This creates an uneven surface texture causing additional noise, vibration, and (eventually) complete failure. It is a costly problem, often leading to unnecessary downtime and expensive repairs or upgrades.
Railroads are one application in particular where electrical current causing pitting is a major cause of bearing failure. Other applications where extra bearing protection is necessary include motors with variable frequency drives (VFDs), pump motors, HVAC units, refrigeration, compressors, generators and data centers.
Emerson Bearing Boston, a bearing company catering to OEMs and Maintenance, Repair and Operations (MRO) markets around the world, offers a solution for preventing electrical bearing damage — replacing standard bearings with ceramic hybrid ball bearings.
Although not all bearings are damaged by an electrical current and not all circuits cause bearing damage, the problem typically occurs when equipment is grounded incorrectly or when bearings are used in AC/DC motors with VFDs.
Ceramic Hybrid Bearing Benefits
Ceramic hybrid bearings consist of ceramic rolling balls and an inner and outer steel race. 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. For example, Nachi ceramic hybrid ball bearings 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.
“Apart from their tremendous insulating properties, there are many other advantages to switching to ceramic hybrid ball bearings – such as safer operation in extreme conditions, a wider range of speed capabilities and longer bearing life span,” explained Steve Katz, president of Emerson Bearing Boston.
He continued, “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.”