Answer Happy

= Q2- Plot the load-efficiency curve for the following motor on a graph paper with distinct points as requested. For how much percentage can we oversize this motor? A de compound motor having a rating of 10 kW, 1150 r/min, 230 V, 50 A, has the following losses at full load: bearing friction loss 40 W brush friction loss 50 W windage loss 200 W (1) total mechanical losses 290 W (2) iron losses 420 W (3) copper loss in the shunt field 120 W copper losses at full load: a. in the armature 500 W b. in the series field 25 W c. in the commutating winding 70 W (4) total copper loss in the armature circuit at full load 595 W 11 l Calculate the losses and efficiency at no-load and at 25, 50, 75, 100, and 150 percent of the nom- inal rating of the machine. Draw a graph showing efficiency as a function of mechanical load (neglect the losses due to brush contact drop).