Motor Shaft Grounding

A Motor Shaft Grounding Module (or for short, a MSGM) is a device used to divert harmful electrical voltages away from motor bearings, preventing bearing frosting or fluting and extending the lifespan of the motor.

Aaki motor shaft grounding modules provide a low-resistance path for electrical currents to flow to the ground, rather than passing through the motor’s bearings. This is achieved using a highly conductive copper graphite conductive brush that maintain contact with the motor shaft while the motor is running. For a more detailed explanation of the theory

Yes, by preventing electrical damage to the motor’s bearings, a MSGM can significantly extend the motor’s operational lifespan, especially in environments shaft currents are generated through the use of Variable Frequency Drives

Variable Frequency Drives are the usual culprit, so any motor that is using some form of speed control is a good candidate for MSGMs. In these varied applications, MSGMs are instrumental in enhancing motor performance and extending their operational life by preventing electrical bearing damage.

We designed the motor shaft grounding modules to be very easy to install. For shops that expect to install more than a few, we have a number of drill templates, spacers and extensions to help the installer deliver a professional looking product in less time and with less effort.

Its a good question and slightly difficult to answer.  The brushes are high quality and made with 70% copper, which typically means they will last a long time:  3 to 10 years is typical and often they will last the life of the motor bearings.  There are a few factors that can decrease the longevity

To maximize the module’s lifespan: Perform monthly inspections during the first six months to establish the wear rate, then adjust the inspection frequency accordingly. Use the Brush Life Window™ for quick and easy monitoring of the brush’s condition. Based on the initial wear observations, create a tailored maintenance plan to extend the module’s life and

We recommend on motors over 5 Hp that two units be installed where possible (one at each end of the motor on both shafts).

Unfortunately, there is no easy way to know or even measure if your electric motor system is generating eddy currents that can damage your bearings. It depends upon many factors such as motor condition, motor load, RPM, grounding conditions, etc. Some electric motor systems can operate for years without a problem and then a change

When electric motors are being driven by VFD’s there is a likely chance that the bearings will fail without a MSGM installed. MSGMs are almost always installed when a motor sent in for repair was being driven by a VFD. However, many of our customers put these on brand new motors prior to commissioning. The