CR4® - The Engineer's Place for News and Discussion®

 Previous in Forum: 400kV Cable Installation Next in Forum: BDV of Transformer Oil
Commentator

Join Date: May 2009
Location: Mumbai
Posts: 73

Derivation of N=120f/P

04/07/2011 12:31 PM

Speed of Induction motor is given by, N= 120f/p

I am searching the derivation of this formula.if anybody have an idea pl. help.

__________________
Thanks
Interested in this topic? By joining CR4 you can "subscribe" to
Guru

Join Date: May 2007
Location: NYC metropolitan area.
Posts: 3003
#1

Re: Derivation of N=120f/P

04/07/2011 1:29 PM

Nobody can help you derive that formula for an induction motor since it is the formula for a synchronous motor. Try Googling, if that fails look in any textbook on electrical machine theory.

__________________
Curious minds want to know, engineering minds get answers....
Guru

Join Date: May 2009
Location: Richland, WA, USA
Posts: 20026
#2

Re: Derivation of N=120f/P

04/07/2011 8:14 PM

This formula is much too easy to require a "derivation." It's just a matter of counting poles as they go by, one per each half of a sine wave.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Guru

Join Date: Oct 2009
Posts: 2029
#3

Re: Derivation of N=120f/P

04/08/2011 10:04 AM

Please refer to any good text book on AC Machines.

Guru

Join Date: May 2008
Posts: 1796
#4

Re: Derivation of N=120f/P

12/14/2016 3:26 AM

Dear Mr.dhanesh koshti,

Pl. refer Electrical Technology book, the AUTHOR is H.C.COTTON

You will find the details in the chapter for Synchronous Generator (and or) Synchronous motor.

The philosophy involved is - how many times the pole crosses a particular set of coil per second.

DHAYANANDHAN.S

Guru

Join Date: May 2009
Location: Richland, WA, USA
Posts: 20026
#5

Re: Derivation of N=120f/P

12/14/2016 5:06 AM

Imagine that.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.