What are the purpose of no load test of an induction motor?

No Load Test is an indirect method used for determining the efficiency and also to determine the circuit parameters of the equivalent circuit of the three-phase induction motors. The open-circuit test is performed on the transformer. The no-load test is the same as the open-circuit test performed on the transformer.

Why block rotor test of an induction motor is carried out?

A blocked rotor test is normally performed on an induction motor to find out the leakage impedance. Apart from it, other parameters such as torque, motor, short-circuit current at normal voltage, and many more could be found from this test. Blocked rotor test is analogous to the short circuit test of transformer.

Why no load test is performed at rated frequency and blocked rotor test is performed at reduced frequency?

This test should be performed at a reduced frequency. In order to obtain accurate results, the Blocked Rotor Test is performed at a frequency 25 percent or less than the rated frequency. The leakage reactances at the rated frequency are obtained by considering that the reactance is proportional to the frequency.

What is the purpose of load test of induction motor?

The load test on induction motor is performed to compute its complete performance i.e. torque, slip, efficiency, power factor etc.

Why blocked rotor test is called as short-circuit test?

It is also known as short-circuit test (because it is the mechanical analogy of a transformer short-circuit test), locked rotor test or stalled torque test. From this test, short-circuit current at normal voltage, power factor on short circuit, total leakage reactance, and starting torque of the motor can be found.

What is the purpose of a load test on the induction motor?

Why blocked rotor test is called as short circuit test?

Which loss in the motor is significant in no load test Why?

Since the motor is not supplying any load, the no-load current is small and stator copper losses are negligible. The input power, W o equals mechanical and core losses. To be more accurate the stator copper loss at no-load current should be deducted from the input when calculating the above losses.

What is a no load test?

The open-circuit test, or no-load test, is one of the methods used in electrical engineering to determine the no-load impedance in the excitation branch of a transformer. The no load is represented by the open circuit, which is represented on the right side of the figure as the “hole” or incomplete part of the circuit.

What information are obtained from no load and block rotor test on single phase IM?

No-Load Test on Single-phase Induction Motor In the no-load test of the motor, the motor is run without load at the rated voltage and rated frequency. The voltage, current and power input are measure using voltmeter, ammeter and wattmeter respectively.

How to test blocked rotor test of induction motor?

Process of Testing of Blocked Rotor Test of Induction Motor. In block rotor test, the low voltage is applied so that the rotor does not rotate and its speed becomes zero and full load current passes through the stator winding. The slip is unity related to zero speed of rotor hence the load resistance becomes zero.

What is no-load test of motor?

No-Load test. Blocked-rotor test. The no-load test of an induction motor is similar to the open-circuit test of a transformer. The motor is not connected from its load, and the rated voltage at the rated frequency is applied to the stator to run the motor without a load.

How to improve the performance of an induction motor?

To improve its performance characteristics certain tests have been designed like no-load test and block rotor test, etc. A blocked rotor test is normally performed on an induction motor to find out the leakage impedance.

Why no load test is performed on synchronous speed induction motor?

As the name suggest no load test is performed when rotor rotates with synchronous speed and there is no load torque. This test is similar to the open circuit test on transformer. Actually, to achieve synchronous speed in an induction motor is impossible. The speed is assumed to be synchronized.