Setting neutral on a DC motor is one way to extend the motor’s brush life and in turn prolong the motor’s lifespan. Motor longevity is largely affected by brush film. Maintaining brush film relies on a number of factors, including setting neutral. Setting neutral is important to prevent sparking. It also regulates motor speed and loading. Without a neutral brush setting, erosion can impact the motor and prevent it from functioning properly. Erosion can be caused by a wear condition like threading or an improper commutator film. Setting neutral involves isolating the brushes and the commutator by installing insulation paper.