Metal Fiber Brushes (MFBs) for Grounding Applications

Metal Fiber Brushes (MFBs) for Grounding Applications

Defense Holdings, Inc.® (DHi) HiPerCon, LLC® of Charlottesville, VA have teamed to extend the use of their revolutionary, patented Metal Fiber Brush (MFB) technology to the grounding of the shafts of electric motors.

DHi’s MFB shaft grounding device is a cost effective means of preventing bearing damage that often is the result stray currents induced in the shafts of electric motors. Without shaft grounding devices current can pass through the motor bearings and end up etching the races and causing premature failure. This problem is particularly acute in variable frequency drive (VFD) motors. VFD motors are used increasingly for many applications including productions lines, printing, fresh water and fire pumps because of the energy savings that they can provide. DHi’s patented MFB technology offers a brush system that can withstand severe operational environments with a very long life.

DHi grounding brushes can:

  • Demonstrate a service life of more than 10 years or 9.1 Billion shaft revolutions at shaft speeds up to 20 meters/sec
  • Operate with up to 60 mils of shaft runout
  • Be easily adapted to any motor using standard mounting options and requires only offer a very small footprint
  • Run directly on a steel shaft without modification
  • Be easily replaced during operation.
  • Carry 40 amps continuous current in a single brush
  • Have a total system resistance of only about 3.7mΩ when operating on a bare steel shaft
  • Operate in oil soaked environments
  • Save additional money because DHi MFBs use silver alloy fibers which are much less expensive than the gold fibers used by some competitors

Don’t be fooled by claims of a shaft grounding system that lasts forever. Any shaft grounding device must make contact with the rotating shaft to conduct current. Contact of two metals in relative motion always results in friction at the point of contact. DHi’s brushes have a long service life because they incorporate the very low wear rates of a light spring pressure MFB with very long fibers running on their tips.