hey guys:

i have this problem that i cant solve

Q/ 250V,15KW shunt motor has a total armature resistance of 0.5 ohm and fiend resistance of 125 ohm . if it takes a current of 5A at no-load find :

1- input current and efficiency at full-load
2- maximum efficiency and its input current

any help is much appreciated

thanks

 

Hello,

Would this page be of any help?
http://www.bowest.com.au/library/machines.html#04

This is a link from the EDUCYPEDIA on motors:
http://educypedia.karadimov.info/electronics/motor.htm

Bertus

 

thanks for the links but i already know these formulas all that is stopping me is a relationship between input current in no-load and full-load

here is the answers :

1- I=75.9 A , efficiency =79%
2-I=51.9 A , efficiency =80.8%