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Why does the rpm of a three phase motor decrease as the number of poles increase?
Wiki User
∙ 9y ago
The synchronous speed is 6000 divided by the number of poles for a synchronous motor on 50 Hz, and 5-10% less than that for an induction motor. On a 60 Hz supply these speeds are 20% higher.
Wiki User
∙ 9y ago
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Why variable voltage and variable frequency control is used instead of variable voltage?
variable voltage control has some limitations as you decrease the voltage corresponding phase current will increase lead to increase of flux which lead to saturation of motor core and heating of motor to make flux constant and vary speed of motor v/f ratio need to be maintained constant
How do you calculate the number of turns that are required for the coils of three phase AC motor?
There is software that can be downloaded to help calculate the number of turns for a three phase motor. There are also diagrams which can be found for the most frequently used calculations.
Can a bad circuit breaker on a 3 phase motor cause the motor to run backwards?
No. If the motor runs backwards, swap any two phases to reverse the rotation, like this: Old wiring: phase A - brown wire - motor lead T1 phase B - yellow wire - motor lead T2 phase C - orange wire - motor lead T3 New wiring: phase A - brown wire - motor lead T2 phase B - yellow wire - motor lead T1 phase C - orange wire - motor lead T3
Will 220 volt work in a high volt 3 phase motor?
Yes a 208 voltage motor will operate on 220 volts. You have to increase the motor overload protection by 10% of the motor's full load amperage to protect the motor.
How do you increase starting torque in cage type 3-phase induction motor's?
by adding external resistance to the shaft of rotor
What are the various method of speed control of 3 phase induction motor?
you can control the speed of a motor by changing frequency, increase or decrease the field winding or by voltage regulation. in these method you can controle the speed of athree phese motor SANDEEP SARKAR
Single phase motor speed is determined by the?
Motor's number of poles.
Why variable voltage and variable frequency control is used instead of variable voltage?
variable voltage control has some limitations as you decrease the voltage corresponding phase current will increase lead to increase of flux which lead to saturation of motor core and heating of motor to make flux constant and vary speed of motor v/f ratio need to be maintained constant
What happens to volume during phase changes?
Volume increases with increase in temperature, and decreases with decrease in temperature.
What is the name of the process that occurs when the particles of a substance experience an increase or decrease in their freedom of movement?
A Phase Change
Why the retention time will decrease if the polarity of mobile phase increase in normal phase HPLC?
because in normal phase HPLC mobile phase is non polar and stationary phase is polar. Most of the compound of interest are polar, if you increase the polarity of mobile phase compound of analyte will stay in mobile phase and will elute faster and retention time will be shorter.
How do you calculate the number of turns that are required for the coils of three phase AC motor?
There is software that can be downloaded to help calculate the number of turns for a three phase motor. There are also diagrams which can be found for the most frequently used calculations.
Can a bad circuit breaker on a 3 phase motor cause the motor to run backwards?
No. If the motor runs backwards, swap any two phases to reverse the rotation, like this: Old wiring: phase A - brown wire - motor lead T1 phase B - yellow wire - motor lead T2 phase C - orange wire - motor lead T3 New wiring: phase A - brown wire - motor lead T2 phase B - yellow wire - motor lead T1 phase C - orange wire - motor lead T3
Will 220 volt work in a high volt 3 phase motor?
Yes a 208 voltage motor will operate on 220 volts. You have to increase the motor overload protection by 10% of the motor's full load amperage to protect the motor.
Is 3 phase motor run on 1 phase supply?
No. That would be a single phase motor.
How do you increase starting torque in cage type 3-phase induction motor's?
by adding external resistance to the shaft of rotor
When heat is added to a situation what 3 things happen?
- the volume increase- the density decrease- a chemical reaction may occur- a change of phase is possible
