I want speed range from 800 rpm to 5000rpm ....for that i m using ac motor ...can you help me how to use it?

i want motor specification which will meet this requirement ..plz help me

changing the revs in an ac motor requires you to change the frequency of the supply. revs = number of 120 x frequency / poles. thus a two pole machine on 50 hz will rotate at 3000 rpm. thus a variable speed drive is required.

I think you would be better off using a dc motor. but not knowing what your trying to do (how much torque/ Hp or application ) , it is near impossible to suggest anything..