Twentieth century handbook for steam engineers and electricians, with questions and answers; a practical nontechnical treatise .. (1916)
Swingle, Calvin F. (Calvin Franklin), b. 1846 · Chicago, F.J. Drake & company · leaf 1095
nstant changing of the po-sition of the brushes and commutator. Whatever style of brush is used, the commutator shouldbe kept clean and allowed to polish or glaze itself whilerunning. Xo oil is necessary unless the brushes cut, andthen only at the point of cutting. A cloth (not cottonwaste)… … Fig. 452 smoothed with sandpaper, never using emery cloth, becauseemery is a conductor of electricity, and the particles ofemery are liable to lodge themselves between the commuta-tor bars in the mica and short circuit the two bars, therebyburning a small hole wherever such a particle of emery…
