NEMA Code Letters for AC Motors
NEMA Code Letters for Locked-Rotor KVA
The letter designations for locked-rotor kVA per horsepower as measured at full voltage and rated frequency are as follows.
| Letter Designation | KVA per Horsepower* |
| A B C | 0.0 – 3.15 3.15 – 3.55 3.55 – 4.0 |
| D E F G | 4.0 – 4.5 4.5 – 5.0 5.0 – 5.6 5.6 – 6.3 |
| H J | 6.3 – 7.1 7.1 – 8.0 |
| K L M | 8.0 – 9.0 9.0 – 10.0 10.0 – 11.2 |
| N P R S | 11.2 – 12.5 12.5 – 14.0 14.0 – 16.0 16.0 – 18.0 |
| T U V | 18.0 – 20.0 20.0 – 22.4 22.4 – & up |
*Locked kVA per horsepower range includes the lower figure up to, but not including, the higher figure. For example, 3.14 is designated by letter A and 3.15 by letter B.
Reference: NEMA Standards MG 1 – 10.37.2.
Code Letters Usually Applied to Ratings of Motors Normally Started on Full Voltage
| Code Letters | F | G | H | J | K | L | |
| Horse- | 3-phase | 15 up | 10 – 7½ | 5 | 3 | 2 – 1½ | 1 |
| 1-phase | – – – | 5 | 3 | 2 – 1½ | 1 – ¾ | ½ | |
Starting KVA per Horsepower for Single-Phase Motors
| Starting KVA per hp = | Volts x Locked-Rotor Amps 1000 x hp | 1 for 1 Ø |