2 pole 4 pole 8 pole motors

In summary, 4 pole motors have 90 degree windings, 6 pole motors have 120 degree windings, 8 pole motors have 160 degree windings, and 10 pole motors have 200 degree windings.
  • #1
tenders
2
0
Hi All,

Can anyone care to explain what are 2 pole 4 pole 6 pole 8 pole motors?
What are the Asian Countries specfically use for them?
 
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  • #2
I assume you mean an induction motor. On a 60 hz system a 2 pole motor runs at 3600 RPM minus slip. 4 pole would be half of this speed, 8 pole a quarter, etc. Wiki should have something on this if you want more detail.
 
  • #3
A 2-pole motor is one where when you go around the outside circumference of the stator, you can count 2 windings. Because they are two, they are diametrically opposed to each other. This 2 windings are connected in a way that when current flows through them, they produce magnetic fields of alternate polarity when you look at them while going around the outside circumference of the stator. So, for example, when one has its North pole on the "outside" of the stator (and its south pole in the inside) the other one has its South pole on the "outside" and its Norht in the inside and so, just like to magnets in series, these two field are actually in the same direction and they join.

A 4-pole motor is one where when you go around the outside circumference of the stator, you can count 4 windings. Because they are 4, they are 90 degrees apart from each other. This 4 windings are connected in a way that when current flows through them, they produce magnetic fields of alternate polarity when you look at them while going around the outside circumference of the stator.

A 6-pole motor...

An 8-pole motor...

By the way, you did not mention anything about phases...what I have described above, applies on a per-phase basis. In other words, if you have a 4-pole 3-phase motor, then it will have 4 windings, 90degrees apart for one phase, 4 more 90deg apart for the second phase and 4 more 90deg apart for the third phase...these sets of 4 windings will be 360/(#phases) degrees rotated from each other; for 3-phase motor, this is 120deg.
 
  • #4
the more poles the motor has, the slower it will turn but the more torque it will have

suppose that you give it a constant power output, with a constant AC frequency (if it is a magnetic rotor brushless motor, a brushed motor uses DC while an induction motor works by turning slower than the input frequency, so you cannot control the speed of those motors directly)

the time it takes to go from one pole to the next pole would therefore be constant (even if you are using other types of motors, just assume that is the case for now) , so you divide by the number of poles to find out the rate at which the motor will turn

and because power = rpm X torque ... to find the resulting torque of the motor, you multiply the number of poles

that is how it works in principle, its a very rough approximation but it is basically correct
 
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  • #5
carmatic: Thank you very much
 

1. What is the difference between 2 pole, 4 pole, and 8 pole motors?

The number of poles in a motor refers to the number of magnetic poles present in the stator. A 2 pole motor has 2 poles, a 4 pole motor has 4 poles, and an 8 pole motor has 8 poles. This means that the stator of a 2 pole motor will have 2 sets of windings, while a 4 pole motor will have 4 sets of windings, and an 8 pole motor will have 8 sets of windings.

2. What are the advantages of using a 2 pole motor over a 4 pole or 8 pole motor?

2 pole motors have a higher rotational speed and are more efficient compared to 4 pole or 8 pole motors. They also have a lower starting torque, making them ideal for applications that require high-speed rotation, such as fans and small pumps.

3. Are there any disadvantages to using a 4 pole or 8 pole motor?

4 pole and 8 pole motors have a lower rotational speed compared to 2 pole motors, which may not be suitable for applications that require high-speed rotation. They also have a higher starting torque, which may be problematic for certain applications.

4. What factors should be considered when choosing between a 2 pole, 4 pole, or 8 pole motor?

The main factors to consider when choosing between these motors are the required speed and torque for the application, as well as the power supply frequency. 2 pole motors are more suitable for high-speed applications, while 4 pole and 8 pole motors are better for applications that require high starting torque.

5. Can a 2 pole motor be converted into a 4 pole or 8 pole motor?

No, the number of poles in a motor is determined by its design and cannot be changed. Attempting to convert a 2 pole motor into a 4 pole or 8 pole motor will result in significant changes to the motor's performance and may damage the motor.

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