PPT Slide

Section 13.9: Starting of DC Motors cont.

Example 13.7 cont.

If the field resistance is increased to 100 W , If = 230 V. / 100 W = 2.3 A. and Ia = I - If = 46A. - 2.3A. = 43.7 A. so the speed equation is:

n = (230V. - 0.05W´43.7A.)/(2.3A.´0.0668) = 1483 RPM