In this case, power flows from the mechanical system, to the rotor circuit, then across the air gap to the stator circuit and external electrical system. Ac induction motors are also the most common motors used in main powered home appliances. They have a good efficiency for a low cost and are very robust. Conversion to mechanical power by motors pumps, fans, hvac, refrigeration compressors, power tools, food processors, escalators, elevators. A 3 phase, y connected, 460 volt line to line, 25 horsepower, 60 hz, 8 pole induction motor has the following constants, in ohms per phase referred to the stator.
Installation and maintenance threephase induction motors. Three phase ac induction motors are widely used in industrial and commercial applications. A three phase im, six poles, 50 hz is supplied by a three. These types of motors are known as selfstarting induction motors. There are mainly two types of induction motor on the basis of power supply, single phase induction motor and three phase induction motor. Ac introduction motors have been used in traction applications for a long time. The basic idea of an electric motor is to generate two magnetic fields. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. One singlephase wattmeter plus miscellaneous apparatus as needed. A 3 phase induction motor can be used for different applications with various speed and load requirements. We thank you for making this choice, and would ask you to read the contents of this manual. A 480v, 60 hz, 6pole, threephase, deltaconnected induction motor has the. One single phase wattmeter plus miscellaneous apparatus as needed.
These motors are selfstarting and use no capacitor, start winding, centrifugal switch or other starting device. Code factor is a number which is reserved for class for example, all motors of class a have a fixed code factor which should be multiplied with rated hp in the above equation. Cage induction machines institut fur elektrische energiewandlung. Output power shown by means of this resistance is zero. Squirrel cage and wound rotor or slip rig induction motor. In the case of three phase ac alternating current operation, the most widely used motor is a 3 phase induction motor, as this type of motor does not require an additional starting device. Three phase induction motors master line 3 mounting characteristics powers up to 50,000 kw voltages from 220 to,800 v speed from 3,600 to 300 rpm manufactured in different configurations of cooling methods and degrees of protection, adapting to the operating and environmental conditions. The 3 phase set of currents, each of equal magnitude and with a phase.
Example for this example, refer to the motor equivalent circuit and calculations described above. The threephase induction motor is the extensively used for various kinds of industrial drives. A 12pole, 3phase alternator driven at a speed of 500 r. Find the starting current of 10 hp, three phase 220 v a class motor. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. The rotor will constantly be turning to align its magnetic field with that of the stator field. Starting of 3 phase induction motors, high starting torque motors.
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