The label of a Europeanbuilt 3phase induction motor includes

The label of a European-built, 3-phase induction motor includes the following: How many poles does the motor have? Explain. What is the motor efficiency when used in North America? Does the motor produce more torque in Europe or in North America? Explain.

Solution

a) n (rpm) = (60 x f) / N

1480 = 60 *50 / N

N = 2 pairs of poles

b) Efficiency = Output power / Input Power * 100

55000 / 380 * sqrt(3) * 101 * 0.87

0.95

c) The motor functions better in North America as the heating losses of the motor is less. A motor should always have a high insulating temperature and a low operating temperature, to keep the windings long lasting