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 of the MSGM.
- The condition of the shaft also plays a big part of brush life. Rough shafts will tend to wear the brush down quicker. However, this kind of wear typically slows down as the copper brush tends to fill the pores of a rough shaft effectively providing a smoother wear surface.
- The environment the motor operates in can significantly reduce brush life. High dust areas or areas with corrosive or abrasive particles in the are can adversely impact brush life.
- High levels of VFD generated eddy currents and shaft voltages can reduce brush life significantly.
We recommend performing an inspection on the modules at least monthly for the first 6 months to determine a wear rate. Our proprietary Brush Life Window(tm) on our motor shaft grounding modules makes it easy to quickly check remaining brush life. From there a scheduled inspection and maintenance plan can be developed that will ensure your motor shaft grounding modules perform their function and operate for years.