Electrical discharge damage, often referred to as Bearings are designed to support mechanical loads, not electrical currents.
When voltage potential builds up between rotating and stationary components, the lubricating oil film may be punctured. Electrical current then passes through the bearing, creating microscopic electrical arcs between rolling elements and raceways.
These electrical discharges generate extremely high localized temperatures, melting small areas of the bearing surface and altering the material structure.
Over time, repeated discharges can severely reduce bearing life and compromise equipment reliability., is a common failure mechanism in rotating equipment. The problem is particularly prevalent in applications using variable frequency drives (VFDs), generators, electric motors and wind turbines.
Even small electrical currents passing through a bearing can cause significant surface damage over time, leading to vibration, noise and premature bearing failure.
Bearings are designed to support mechanical loads, not electrical currents.
When voltage potential builds up between rotating and stationary components, the lubricating oil film may be punctured. Electrical current then passes through the bearing, creating microscopic electrical arcs between rolling elements and raceways.
These electrical discharges generate extremely high localized temperatures, melting small areas of the bearing surface and altering the material structure.
Over time, repeated discharges can severely reduce bearing life and compromise equipment reliability.
Several factors can contribute to electrical current passing through bearings:
Identifying the root cause is essential, as replacing the bearing alone will not eliminate the underlying problem.
Early identification of electrical discharge damage allows operators to implement corrective actions such as:
Detecting damage at an early stage reduces unplanned downtime, lowers repair costs and improves overall asset reliability.
Electrical discharge damage is commonly associated with the following damage mechanisms:
Once electrical damage has started, it tends to progress rapidly due to the deterioration of rolling contact surfaces.
Electrical discharge damage rarely occurs overnight. In most cases, it develops gradually until vibration, noise or secondary bearing failures become apparent.
Understanding the characteristic damage patterns associated with bearing currents enables maintenance teams to identify problems early and address root causes before costly failures occur.
Professional bearing inspections provide valuable insight where eyes can’t reach.