The capacitor motor is slightly different from a split-phase motor. A capacitor is placed in the path of the electrical current in the start winding (see Fig. 7-13). Except for the capacitor, which is an electrical component that slows any rapid change in current, the two motors are same electrically. A capacitor motor can usually be recognized by the capacitor can or housing that is mounted on the stator (see Fig. 7-14).
Adding the capacitor to the start winding increases the effect of the two-phase field described in connection with the split-phase motor. The capacitor means that the motor can produce a much greater twisting force when it is started. It also reduces the amount of electrical current required during starting to about 1.5 times the current required after the motor is up to speed. Split-phase motors require 3 or 4 times the current in starting that they do in running.
Categories: Electric Motors | Tags: Capacitor-start motor | Leave a comment