Setting of the Brush Holders

Setting of the Brush Holders

When setting the brush holders, make sure the distance between the brush holder and the commutator surface is not bigger than 2mm, and the brush holder arms are parallel to the segments of the commutator. When setting the brush holders and carbon brushes, there are three positions that can be selected according to the rotating direction of the commutator. These three positions are called: Trailing, Reaction and Radial. On motors with bi-directional operation it is recommended that the carbon brushes are set on a Radial position on the commutator as the forces applied will be almost the same on both directions. The same rule will apply to carbon brushes set with a Trailing angle of 7.5° that can operate in forward and reverse, or single direction. On Reaction position, carbon brushes must be made with a set angle on top of the brush, where the spring pressure is applied, to be directly opposite to the direction of rotation of the commutator.

Incorrect
Correct
Radial Brush Holder 
Trailing Brush Holder 

Reaction Brush Holder