In those cases where galvanic currents pass through motor’s bearings they can damage them. The grounding brushes’ most important function is to prevent the current from passing through the bearings and thereby prevent damage. Galvanic currents cause small pits and grooves which result in higher friction in the bearing. Metal graphite brushes with high metal content are usually used for carbon grounding brushes.
Silver graphite is the best choice because silver materials are less affected by oxidation, but copper graphite can also be used. Pure metal graphite brushes cannot cope with such high peripheral speeds.
At higher peripheral speeds additional lubrication may be required. We recommend sandwich-type brushes which consist of graphite that lubricates and silver graphite that gives low resistance.
Our carbon brushes grounding contacts are known for their long service life and reliability. Our carbon brushes grounding contacts are also characterized by their long service life and reliability