Electrical Motors - Locked Rotor Design Code Letters

NEMA locked rotor indicating code letters for electrical motors. Classifies motors by the ratio of locked rotor kVA per horsepower according to NEMA standards.

NEMA Code LetterkVA/HP with locked rotorApproximate Mid-Range Value
A0 - 3.141.6
B3.15 - 3.553.3
C3.55 - 3.993.8
D4.0 - 4.494.3
E4.5 - 4.994.7
F5.0 - 5.595.3
G5.6 - 6.295.9
H6.3 - 7.096.7
J7.1 - 7.997.5
K8.0 - 8.998.5
L9.0 - 9.999.5
M10.0 - 11.1910.6
N11.2 - 12.4911.8
P12.5 - 13.9913.2
R14.0 - 15.9915.0
S16.0 - 17.99
T18.0 - 19.99
U20.0 - 22.39
V22.4 - and up

Standard 3 Phase Motors Locked Rotor Codes by Horsepower

  • Less than 1 hp: Locked Rotor Code L, 9.0 - 9.99 kVA
  • 1 1/2 to 2 hp: Locked Rotor Code L or M, 9.0 - 11.19 kVA
  • 3 hp: Locked Rotor Code K, 8.0 - 8.99 kVA
  • 5 hp: Locked Rotor Code J, 7.1 - 7.99 kVA
  • 7.5 to 10 hp: Locked Rotor Code H, 6.3 - 7.09 kVA
  • More than 15 hp: Locked Rotor Code G, 5.6 - 6.29 kVA

Note: Small motors generally require higher starting kVA than larger motors. The starting kVA required by a motor starting at full voltage is determined from the nameplate on the motor or from the manufacturer.