Share with your Facebook friends! At anything less than full load, power factor of the induction motor is less than its rated power factor because the torque producing current decreases as the load decreases, but the magnetizing current does not change. The applications of industrial engineering pdf the load, worse the power factor.
Motors selected from a standard range are almost always chosen with a rated power in excess of maximum load demand, with the result that in any installation the motors seldom operate at their full rated load. Consequently, they can never achieve their rated power factor even at a maximum load demand. More over, if the load is variable. Further, the cost charged is increased if demand exceeds a maximum limit. Typically, more than 7 times it’s rated full load current.