... (2) With a good flow properties and set to change commutation , so that spark suppression in the permitted ... no heat, noise, broken, what’s more never change color carbon brush‘s body, no ablation. (4 ... , brush wear, and commutator wear.Machine Neutral:To obtain optimum machine performance, the brush must be ... sparking under a no-load condition. Depending upon how far off neutral the machine is set, ...