NEMA Motor Design letter designation based upon standards established the
National Electrical Manufacturers Association that corresponds
to motor’s speed and torque characteristics. Motors too large correspond NEMA frame
sizes are referred above NEMA motors.
480 Volts
480 Volts
480 Volts
277 Volts
277 Volts
A
C
Neutral
277 Volts
3-Phase, 4-Wire (Wye-Connected) Transformer Secondary
480 Volts Phase-to-Phase, 277 Volts Phase-to-Neutral
B
N
Ohm The basic unit resistance, reactance and impedance.
Ohmmeter meter designed measure resistance.The
symbol for the ohm “W”
, the Greek letter omega.
.24
NEMA Frame Size designation that identifies motor dimensions based upon
standards provided the National Electrical Manufacturers
Association.
300
275
250
225
200
175
150
125
100
75
50
25
0
0 100
NEMA D
NEMA C
NEMA B
%
Full-Load
Torque
% Synchronous Speed
Full-Load Torque
Neutral reference connection power distribution system
