Bearing current remediation methods

A number of options are available for reducing or eliminating the current flows, the appropriateness of each depending on the type and source of the bearing current found.

The Table lists bearing current remediation methods for the various current paths. Each row in the table corresponds to a type of shaft and bearing current. Each column represents a potential solution. An “X” in the table indicates that the remedy, by itself, would reduce or eliminate bearing damage due to that particular component of bearing current. If you expect multiple current paths in a given application, you'll need to use multiple remediation methods.

Note that the list shows no single motor construction or system installation method that will remedy all bearing current components. Also, note that some remediation methods may reduce currents in one part of the system while increasing damaging current flow in other parts of the system.

The following are currently available bearing current remediation methods:

• Improve the high-frequency grounding connection from the motor to the drive and from the motor to the driven equipment.
• Install one insulated bearing on the opposite drive end of the motor.
• Install two insulated bearings on the motor.
• Install a shaft grounding brush across one motor bearing.
• Install a Faraday shielded motor.
• Install an insulated coupling between the motor and the driven equipment.

Implementing the correct remediation method depends on your understanding of the potential current paths in a given installation. But identifying these high-frequency paths isn't always easy. Proper grounding is key to shunting currents away from paths that flow through motor or driven equipment bearings. You should also have a thorough understanding of inverter/motor/driven equipment systems.

Linqing Nine Star Bearing Science & Technology Co., Ltd 

( Insulated bearing, Hybrid ceramic bearing and  Brass cage DGBB)

Follow us via E-mail info@jxkjzc.com; Website www.ninestarbearing.com