What is the formula for rotor bar current?

What is the formula for rotor bar current?

With increased rotor resistance starting torque will increase. As a guide line the rotor bar current density can be assumed between 4 to 7 Amp/mm2 or may be selected from design data Hand Book. Hence sectional area of the rotor bars can be calculated as Ab = Ib /δb mm2.

What is the current in the rotor?

Locked rotor current is basically the current drawn by the motor at its rated voltage when its rotor is kept stationary or in other words rotor is not spinning or rotating. So when we start a motor, its rotor is already at rest. This means, starting current and locked rotor current should be same.

How do you calculate copper rotor loss?

The rotor copper loss is calculated by subtracting the stator copper loss from the total measured loss or the rotor I2R loss….Losses Calculation

1. Core loss in the stator and the rotor.
2. Stator and rotor copper losses.
3. Friction and windage loss.

What determines the magnitude of rotor current?

The magnitude of the rotor currents depends on the slip and on the impedance (comprising resistance, and inductive reactance proportional to slip) of the rotor windings.

Which type of rotor is used in 3 induction motor?

There are two types of induction motor rotors: Squirrel-cage rotor or simply cage rotor. Phase wound or wound rotors.

How is rotor bar frequency calculated?

Loose or open rotor bars in AC induction motors are indicated by a 2 X line frequency (2 FL) sidebands surrounding rotor bar pass frequency and/or its harmonics (rotor bar pass frequency = number of bars X rpm).

How to calculate the rotor speed of an induction motor?

Calculation: The rotor speed of a 4 pole induction motor at 50 Hz is 1200 r/min. Calculate its slip. Solution: Rotor speed = η m = 1200 r/min Where η sync = 120 * 50 / 4 = 1500 r/min

How is a 3 phase induction motor calculator used?

3 Phase Induction Motor current calculator is used to calculate the rated and full load amperes of the motor. Enter the rated volts, amps, power, and efficiency to find the current flowing through the motor. The 3 phase Induction motor is popular for its efficiency and is widely employed in the electric systems for doing mechanical work.

How to calculate the SS of an induction motor?

The SS is a function of the frequency of the power source and the number of poles (pole pairs) in the motor. The relationship to calculate the SS of an induction motor is: 1 SS = (120 X f) / P Where: SS = Synchronous Speed (RPM) f = frequency (cycles / second) = 60 P = number of poles (pole pairs) Examples:

How to calculate the torque of a 10 HP induction motor?

Calculation: Find the shaft torque of the 10 hp induction motor whose rotor speed is 1500 r/min. Solution: τ ind = (10 hp * 746 kW/hp) / (1500 r/min * 2 π rad/r * 1 min/60 s) = 47.49 Nm I L = S start / (√3 * V T ), where S start = Rated HP of the motor * Code factor