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On an AC motor you basically vary the frequency on a DC you can vary the voltage.

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Q: How do you change the speed of motor without change pole and frequency?
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How do you change AC motor speed?

A change in frequency of the motor will cause a change in the speed of the AC conveyor motor. This frequency change is brought about by a device called a Variable Frequency Drive. It is used to vary the frequency of the motor from 0 to 100%. I have no idea what the second answer is talking about. ANSWER: considering that no mention of type of motor is involved the frequency change theory is quite invalid since 50 or 60 Hz AC line runs clocks from banks to wake up calls and while it is true that the frequency is not accurate from second to second it is however very accurate from minutes to minutes.


When induction motor is switched on the rotor frequency is?

The induction motor rotor has different frequency compared to it's stator. The rotor has slip ( s ) frequency. slip = ( Synchronous speed - rotor speed ) / Synchronous speed Synchronous speed = ( 120 * f ) / P where f = supply frequency to the stator. p = no of poles rotor speed is the actual speed the motor is running. Frequency in the rotor = slip * frequency in the stator At starting rotor speed is zero, so slip is one. Let us take the supply frequency is 50 Hz, then rotor frequency is also 50 Hz at starting. The motor attains speed and runs with its full speed at a point of time. Then let us take the slip is 0.04 then the rotor frequency will be 2 Hz.


How does a frequency inverter work?

A frequency converter converts alternating current of one frequency to alternating current of another frequency. Generally it's used for controlling the ac motor speed by changing the supply frequency.


Can you run a 230v 60HZ motor on 230v 50HZ power?

You may or you may not. It all depends on the task you are using the motor. If speed is not a concern for you then you may, but for sensitive systems where changes in motor speed affects the system then you may not. The reason is that the frequency of the power supply affects the motor speed. Frequency is directly proportional to speed.


How do you change the direction of rotation of synchronous motor?

A synchronous motor aways runs at the synchronous speed, which is the supply frequency divided by the number of pairs of poles in the motor. For a 4-pole motor the speed is 1500 rpm (50 Hz supply) or 1800 rpm (60 Hz supply). The mechanical phase of the rotor is liable to be a little unstable under changing load conditions.

Related questions

How do you reduce the speed of a 15 kW 3 phase motor without using variable speed control?

If the load is connected to the motor via belts, you can change the speed the load is turning by changing the pulley sizes. To get the load to slow down, increase the size of the pulley on the load; to get it to speed up, increase the size of the pulley on the motor. To reduce the speed of the motor itself, you'll have to alter the line frequency, which you can't do without a variable frequency drive attached to the motor.


Speed of DC Motor can be controlled by a frequency variable?

by using a frequency tuner in input we can change input frequency and in this way speed of dc motor will also vary. <<>> Varying the frequency (VFD) only works on AC motors.


How do you control the speed on an ac motor?

the speed of ac motor can be controlled by controlling the synchronous speed (Ns=120f/p). and synchronous speed can be varried or controlled by changing frequency or by changing poles. but practicaly pole can not be changed. but we can change the frequency. the frequency can be VFD (Variable frequency Drives). so the speed of ac motor can be chaged or controlled by VFD.


How do you change AC motor speed?

A change in frequency of the motor will cause a change in the speed of the AC conveyor motor. This frequency change is brought about by a device called a Variable Frequency Drive. It is used to vary the frequency of the motor from 0 to 100%. I have no idea what the second answer is talking about. ANSWER: considering that no mention of type of motor is involved the frequency change theory is quite invalid since 50 or 60 Hz AC line runs clocks from banks to wake up calls and while it is true that the frequency is not accurate from second to second it is however very accurate from minutes to minutes.


How a frequency inverter operates?

The frequency inverter changes the frequency of power lines to the electric motor, hence to change the speed of the motor, in some applications like conveyor, it does not need full speed running all the times, so the frequency inverter comes in as the speed control role to save electric energy.


How does an ac drive variable speed drive operate to control speed?

Answer #1 It varies the frequency fed to a synchronous AC motor. As the frequency changes, so does the motor speed. Answer #2 The formula for calculating speed is: (120 X motor supply frequency) / number of poles 120 is a fixed number, so is the number of poles for a given motor, hence the only variable is the motor supply frequency. AC drives vary the motor supply frequency in turn achieving speed control.


How does a Variable speed transmission work?

Assume a 3 phase AC Induction motor. The speed of the motor is derived by the formula N = (120/f)/P. N speed, f - frequency, P number of poles. In an induction motor P is fixed by the winding. f system frequency. Variable speed drives change the system frequency so that the speed (N) can be varied. Drive is a power electronic device through which the system frequency can be varied


If you increase or decrease the frequency what effect on electrical machin?

If you're talking about an electric motor, increasing the frequency will increase the speed of rotation of the motor, and decreasing the frequency will decrease the speed of rotation of the motor. The other way of controlling a motor is to control the current; increasing the current increases speed, decreasing current decreases speed.


How does a frequency drive work?

Frequency drives are an adjustable-speed drive used for electro-mechanical drive systems. They control the motor speed and torque by varying motor input frequency and voltage.


What is the principle of variable frequency drive?

Variable frequency Drive is power electronic device in which electrical power is provided to a motor with desired voltage level and with a facility to change the base frequency to higher or lower frequency. Base frequency is 50 or 60 Hz depending upon the region in the world. The formula for speed in a 3 phase system is N = (120 x Frequency) / Number of poles. N being the speed. By changing the frequency the motor speed can be varied.


When induction motor is switched on the rotor frequency is?

The induction motor rotor has different frequency compared to it's stator. The rotor has slip ( s ) frequency. slip = ( Synchronous speed - rotor speed ) / Synchronous speed Synchronous speed = ( 120 * f ) / P where f = supply frequency to the stator. p = no of poles rotor speed is the actual speed the motor is running. Frequency in the rotor = slip * frequency in the stator At starting rotor speed is zero, so slip is one. Let us take the supply frequency is 50 Hz, then rotor frequency is also 50 Hz at starting. The motor attains speed and runs with its full speed at a point of time. Then let us take the slip is 0.04 then the rotor frequency will be 2 Hz.


Electronic component used to control speed of a motor?

In industrial, there is a device called variable frequency drive (allso frequency inverter, ac drive) to control the motor speed by adjusting output frequency.