NEMA Polyphase Induction Motors Design Code A and B differences

[t_van]

I am reading up on the differences between design code A and B Polyphase motors. Main source of information is NEMA MG-1. From my research, it appears the only difference between the two types is the design code A motor has a higher locked rotor current than design code B. I also read a statement that the higher locked rotor current of a design code A motor translates to an increased full load efficiency. Thoughts?

 

[Besoeker]

I am reading up on the differences between design code A and B Polyphase motors. Main source of information is NEMA MG-1. From my research, it appears the only difference between the two types is the design code A motor has a higher locked rotor current than design code B. I also read a statement that the higher locked rotor current of a design code A motor translates to an increased full load efficiency. Thoughts?

I agree.

 

[Jraef]

I would say it CAN lead to increased efficiency under the right circumstances and compared to other standard motor designs. If efficiency is what you are after, Energy Efficient motors are usually considered Design B from a torque/speed curve standpoint.