What is blocked rotor voltage?

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 the purpose of blocked rotor test?

This test is performed to determine the short circuit current with normal voltage applied to stator; power factor on short circuit; total equivalent of resistance and Reactance referred to stator.

What information is learned in a locked rotor test how does a locked rotor test conducted?

In this test, the shaft of the motor is connected so that it cannot move and rotor winding is short-circuited. In a slip-ring motor, the rotor winding is short-circuited through slip-rings and in cage motors, the rotor bars are permanently short-circuited. This test is also called the locked-Rotor test.

What is the advantage of no load and blocked rotor test?

This test gives the information regarding no-load losses such as core loss, friction loss and windage loss. Rotor copper loss at no load is very less that its value is negligible. Small current is required to produce adequate torque.

What are the various losses occurring in the motor under blocked rotor test?

As explained earlier the rotor losses are of two types rotor iron loss and rotor copper loss. Since the iron loss depends upon the rotor frequency, which is very small when the rotor rotates, so it is usually neglected.

What is the difference between transformer and induction motor?

A transformer transfers electrical power from one circuit to another without changing the supply frequency, i.e. it only step-up or step-down the level of voltage and current, whereas induction motor converts electrical power into mechanical power.

What is the advantage of no load and Blocked Rotor Test?

What are the various losses occurring in the motor under Blocked Rotor Test?

What is the slip of forward and backward rotor?

One rotor rotates in forward direction which is the direction of rotating magnetic field with a slip s while the other rotates in backward direction in the opposite direction of the rotating magnetic field with the magnitude of slip whose value is the forward slip subtracted from two.