The alternating current running with variable frequency driver (VFD) uses pulse width modulation (PWM) to control the motor speed. This means that common mode voltage will be generated on the motor shaft through capacitive induction, which will lead to discharge on the motor bearing, causing EDM pits, electrical corrosion spots and groove damage. The failure rates caused by different factors vary greatly, but there is evidence that a considerable part of failures occur only 3 to 12 months after the system is put into production. All AC and DC motor bearings of the frequency converter may cause this fault, regardless of the size or power of the motor body.

Electric erosion has become the main cause of motor bearing failure, and it is not easy to detect in the early stage, and gradually the motor vibration and noise become greater, eventually leading to unexpected shutdown. The shaft grounding ring uses special conductive fiber materials to guide the induced shaft current to ground through the end cover, so as to avoid damage to bearings and related equipment caused by shaft current, effectively solve the problem of shaft voltage, and avoid electrical corrosion damage to bearings. Variable frequency motor and its coupling equipment are the main application of electric erosion protection ring. Compared with traditional solutions such as carbon brushes and insulated bearings, it has the advantages of high efficiency, maintenance free, long service life and easy installation.

Characteristics of grounding ring:

1.0EM installation or on-site modification and installation;

2. Long service life, maintenance free;

3. Split design, simple installation, modular design, applicable to all types of motors;

4. It can be used in combination with bearing isolator.