Electric motor frame sizes
NEMA frame size refers to the physical dimensions and mounting of the electric motor. They are a key part of motor interchangeability; in essence, a motor from one manufacturer can be replaced with a similar motor from another company provided they are both of the same frame size. The shaft length, shaft diameter, mounting foot dimensions, distance from the center of the shaft to the bottom center of the mounting foot are all part of the frame size standard. The physical dimensions of an electric motor have also been standardized by NEMA where “D” dimensions refers to the distance from center of shaft to bottom center of mounting foot, “U” dimensions refers to the diameter of the shaft, “N-W” dimensions refers to the length of the shaft, “F” dimensions refers to the distance from the center of the mounting foot to the center of base mounting hole in the side view and so on and so forth. A standard Frame size designation for electric motors is either made up of either 2 or 3