Jump to content

4 Poles Or 2 Poles Motor?


AB2005

Recommended Posts

Dear All,

 

We are designing a Trim Waste Blower for our new Flexo machine. Blower designer has mentioned on the drawing that Impeller RPM should be 2250 while he has given us two options about motor i.e.3Phase, 11KW, 50HZ either 4pole or 2pole. Impeller RPM would get by increasing/reducing the sizes of pulleys. I have suggested 4pole motor for thinking that low RPM of motor will increase the bearing life as compare with 2pole motor. What do you think about that?

Thanks for any input.

 

"Don't assume any thing, always check/ask and clear yourself".

Link to comment
Share on other sites

Hello AB2005

The bearing life may be a factor, but provided that the bearings are correctly selected, this should not be an issue.

The major differences will probably be :

The efficiency of the two pole motor may be slightly higher than the four pole motor.

The start curves of the two pole motor will probably be squarer than the four pole making the motor more difficult to start on minimum current. (not an issue on DOL starting) - If you are using a reduced voltage starter this could be important.

 

Best regards,

Link to comment
Share on other sites

Hello AB2005

The bearing life may be a factor, but provided that the bearings are correctly selected, this should not be an issue.

The major differences will probably be :

The efficiency of the two pole motor may be slightly higher than the four pole motor.

The start curves of the two pole motor will probably be squarer than the four pole making the motor more difficult to start on minimum current. (not an issue on DOL starting) - If you are using a reduced voltage starter this could be important.

 

Best regards,

 

Yes, your point is valid.

According to Siemens Catalogue M11, the efficiency of 2pole motor is 91.0 and 4pole motor is 90.5.

We will use a star delta starter for starting that motor.

 

"Don't assume any thing, always check/ask and clear yourself".

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...