0
Motor's number of poles.
Wiki User
∙ 14y ago
Anonymous
Number of stator poles
Add your answer:
Earn +20 pts
Why single phase induction motor has pulsating torque?
according to a mathematical theory the flux produced when an alternating current flows in a single phase winding , this flux is composed of tow equal components which result in tow equal torques , these torques work in opposite direction to each other , hence one causes the rotor to move in a certain direction while the other in the opposite direction . this is the reason why a single phase induction motor instead of its rotor to move in one direction it vibrates. the resultant of these torques is zero. if the motor is caused to move by an external mean say by hand , then the resultant will no longer zero and the motor continue revolving and it speeds up even the external mean is removed, For a single phase induction motor to be a self starting motor some techniques are used like connecting an additional winding called auxiliary winding and a capacitor which in some designs removed automatically when the motor speed come to a certain value while for other designs these elements continue to be connected . Any single phase induction motor is provided by a starting technique so if it vibrates , then this means that the technique is failed
Why would three phase be used instead of single phase?
Three phase electricity is used instead of single phase for industrial situations. Industries use three phase electricity instead of single phase to operate electric motors driving heavy machinery. Three phase electrical motors produce more power from the same amount of electricity and maintain steadier speed. Small portable motors such as drills and mixers use single phase. Motors used around the house are single phase. Motors used to run large industrial machines use three phase.
What can we do to change 3 phase motor into single phase?
The physical internal windings between single phase and three phase motors makes this an impossibility. That being said, money can make anything happen. Depending on the amount of money you want to spend to make this happen, there is a device on the market called a VFD (Variable Frequency Drive). On the three phase input terminals you apply your single phase voltage. On the output terminals you connect your three phase motor. When run in this configuration, there is an internal switch that has to be changed to let the VFD know that it should be looking for only two lines on the input to be hot. Otherwise the VFD thinks that there is a line loss on the three phase input terminals and the unit will not start.As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.If you do this work yourself, always turn off the powerat the breaker box/fuse panel BEFORE you attempt to do any work ANDalways use an electrician's test meter having metal-tipped probes(not a simple proximity voltage indicator)to insure the circuit is, in fact, de-energized.IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOBSAFELY AND COMPETENTLYREFER THIS WORK TO QUALIFIED PROFESSIONALS.
What happens if the high and low speed wires are switched on a 3 phase motor?
I am guessing that what you are talking about is a two speed motor. The motor should have 6 wires coming out of it. There are two complete sets of three phase windings for each speed. Look on the motor name plate for the wire numbers or sometimes on the inside of the motor junction box. A 2 speed 6 lead motor should have the following markings, 1U 1V 1W for slow 2U 2V 2W for fast. Also check for the two different amp draws for each winding. These types of motors should be run from a reversing type contactor assemble so that individual overloads can be used on each of the high speed windings and on the low speed windings.
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.
The synchronous speed of a four pole 60 hz single phase motor is?
3600 rpm
How many Methods can be use to control the speed of Single Phase Induction Motor?
How many methods can be used to control the speed of Single Phase Induction Motor? 1.injecting emf method 2.by frequency control method 3.induced voltage method
How do you reduce the speed of a single phase digital meter 1600mp or kWh 50HZ without reducing the consumer load?
The speed of a single phase digital meter 1600mp or kWh 50HZ can be reduced. By decreasing the voltage to reduce the speed of the single phase digital meter the motor is to decreased in speed meaning the consumer load will be decreased as well.
What is the calculation formula for rewinding a 415v 3 phase single speed motor to 2 speed operation?
5 hp moto 1500 rpm 3 phase winding calculation
What motor gets more heated single phase or three phase?
Your question is a little like asking, 'How long is a piece of string?'! Do the two motors have the same power rating, or are they different?The rate at which energy is used by any machine is defined by its power rating. If the power ratings of two different machines are the same, then both machines use energy at the same rate. So if a single-phase motor has the same power rating as a three-phase motor, then they will both use exactly the same amount of energy over a given period of time.So, if a single-phase motor has a greater power rating than a three-phase motor, then the single-phase motor will the greater amount of energy in a given period. On the other hand, if a three-phase motor has a greater power rating than a single-phase motor, then the three-phase motor will the greater amount of energy in a given period.
Will single-phase Induction motor run on one winding once it has been started?
A single-phase induction motor has a main winding and a starting winding. When the motor has run up to normal speed the starting winding can be switched out, but for small motors this is not usually worth the trouble.
Will a single-phase Induction motor run on one winding once it has been started?
A single-phase induction motor has a main winding and a starting winding. When the motor has run up to normal speed the starting winding can be switched out, but for small motors this is not usually worth the trouble.
How do you wire a three phase motor with two speed to a three phase power supply lead numbers not specified?
There are many types of winding on a two speed three phase motor. The number of wires from the motor should have been stated. This is a guess that the motor is a six lead. The diagram is for a six lead out two speed, one winding, single voltage constant horsepower motor.See sources and related link below
What is difference between frequency and slip frequency?
Both 3-phase induction motors and single-phase induction motors have rotating magnetic fields assuming that the single-phase motor has one of the usual starting mechanisms built-in. The synchronous speed is given by RPM = 120 X f / p where f is the frequency and p is the number of poles. The conductors in the rotor pass through the magnetic field of the stator at the slip speed. As a result an alternating current is generated in the rotor. The frequency of that current is the rotor frequency or slip frequency given by slip frequency = slip speed X p / 120. At full load, the slip speed of a standard, 3-phase motor is about 1% to 2.5% of synchronous speed. A motor with 6% slip would be classified as a high-slip motor. The slip of a standard single-phase motor could be 6%.
Why use clutch plate in single phase motor?
induction motors have very little starting torque as the motor come up to speed it reduces the torque load until it gets near synchronous speed
What is the most efficient type of single Phase motor?
The British Lynch axial-gap dc motor. With a typical efficiency of around 90%, it can achieve the same efficiency as a 3-phase AC motor, but with far easier control over speed and torque.
What are the disadvantages of a three phase induction motor?
The primary disadvantage of the three phase induction motor is that speed control is a challenge. But new technology in the form of VFDs (variable speed drives) is now rectifying this situation very effectively. Another disadvantage is that single phase power is common while three phase power is less commonly available.
