The two primary types of motor enclosures classified by NEMA are​ . A. general purpose and guarded B. open and totally enclosed C. nonventilated and externally ventilated D. guarded and​ semi-guarded

Adouble-strand no. 60 roller chain is used to transmit power between a 13-tooth driving sprocket rotating at 300 rev/min and a 52-tooth driven sprocket. a) what is the allowable horsepower of this drive? b) estimate the center-to-center distance if the chain length is 82 pitches. c) estimate the torque and bending force on the driving shaft by the chain if the actual horsepower transmitted is 30 percent less than the corrected (allowable) power.