is there any engineer can solve this or give me a key of the points ?

 

Yes, but a good engineer knows what her time is worth...

 

In the homework section, you have to show your effort in order to receive guidance.

 

Posted 2/12 and due 12/23 ... too bad your instructor only left you with 10 months and 11 days to complete the project.

 

How do you determine the number of poles and the size of the induction motor (in hp) if the slip is between 0.3 and 0.5?
All I know is that the slip = (synchronous speed - rotor speed)/synchronous speed, synchronous speed = (120*synchronous frequency)/number of poles

 

Of course it is possible that 2/12 means that the project was set on 2nd December and not 12th February (not everybody uses mm/dd/yy , some use dd/mm/yy ) so instead of 10 months and 11 days they only have 21 days.

 

Another way as I know it is Synchronous speed = (60 * Frequency of supply)/Pole Pairs.
Max.

 

Any other suggestions?

 

Of course it is possible that 2/12 means that the project was set on 2nd December and not 12th February (not everybody uses mm/dd/yy , some use dd/mm/yy ) so instead of 10 months and 11 days they only have 21 days.

Very true and after I read where the document originated, I'd have to go with 21 days and not my exaggeration of time which I apologize. I did find it interesting that the Instructor used 02/12/2014 as the posted date but stated it was due 23rd December 2014, a minor inconsistency.

 

Very true and after I read where the document originated, I'd have to go with 21 days and not my exaggeration of time which I apologize. I did find it interesting that the Instructor used 02/12/2014 as the posted date but stated it was due 23rd December 2014, a minor inconsistency.

No more inconsistent that a paper here using 12/02/2014 and then using December 23, 2014 elsewhere would be, which is not too rare to see. I tend to prefer the format 23 Dec 2014 when I can use it but if I have to use the 'slash' notation then I use the MM/DD/YY (or YYYY) convention since that is what most people in my audience will assume.

 

i asked to give me a key

 

i asked to give me a key

And we asked YOU to show some effort to solve YOUR homework. We're still waiting.

 

Hello,

The following pages of the EDUCYPEDIA will give you information on the induction and synchrone motors:
Induction motor
Synchronous motor

This might help you solving part of the problem.
Now show us YOUR effort.

Bertus

 

can you see any mistake ?