If the full load speed of a 3 phase 50 Hz 6 pole induction motor is 950 rpm. What is its half load speed nearly equal to
The starting line current of a 415V,3−phase, delta connected induction motor is 120A, when the rated voltage is applied to its stator winding. The starting line current at a reduced voltage of 110V, in ampere, is _________.
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A 2500 V, 50 Hz delta connected induction motor has a star connected slip ring rotor with a phase transformation ratio of 3.5. At standstill, the rotor resistance and leakage reactance are 0.04 and 0.6 Ω respectively. What is the value of rotor current at 4% slip with slip rings shorted?
A 4 pole induction machine is working as an induction generator. The generator supply frequency is 60 Hz. The rotor current frequency is 5 Hz. The mechanical speed of the rotor in RPM is
A 3 – phase, slip ring induction motor with delta connected rotor has an induced emf of 230 V between slip rings at standstill. Resistance and leakage reactance are 0.5 and 2.5 Ω respectively at standstill. What is the rotor current per phase at rotor developing maximum torque?
The rotor of a 3-phase induction motor has 0.04 Ω resistance per phase and 0.2 Ω standstill reactance per phase. An external resistance is used in the rotor circuit in order to get half of the maximum torque at starting. Neglect stator impedance. By what percentage will this external resistance change the power factor at starting?
The figure shows the per-phase equivalent circuit of a two-pole three-phase induction motor operating at 50 Hz. The “air-gap” voltage, Vg across the magnetizing inductance, is 210 V rms, and the slip, is 0.05. The torque (in Nm) produced by the motor is _______.
Name the starter which is very common and is used for cage motor design to run normally on delta connected stator winding.
In order to______ semi-closed slots or totally closed slots are used in induction motors.
The starter recommended for a 20 hp squirrel cage induction motor is: