Motor Full-Load Current Chart

The code's own motor currents: full-load amperes by horsepower and rated voltage for three-phase induction motors (NEC Table 430.250, 1/2 through 500 HP) and single-phase motors (Table 430.248, 1/6 through 10 HP). Per 430.6(A)(1) these table values — not the nameplate — size the conductors, the short-circuit protection, and the disconnect. Values assume normal-torque motors at usual belted speeds.

Three-phase induction motors (squirrel cage & wound rotor)

NEC 430.250

Full-load current in amperes by horsepower and rated motor voltage for three-phase induction-type squirrel-cage and wound-rotor motors (values per NEC Table 430.250). Currents are permitted for system voltage ranges 110–120, 220–240, 440–480, and 550–600 V. A dash means the table prints no value for that combination.
HP	115 V	200 V	208 V	230 V	460 V	575 V	2300 V
1/2	4.4	2.5	2.4	2.2	1.1	0.9	—
3/4	6.4	3.7	3.5	3.2	1.6	1.3	—
1	8.4	4.8	4.6	4.2	2.1	1.7	—
1½	12	6.9	6.6	6	3	2.4	—
2	13.6	7.8	7.5	6.8	3.4	2.7	—
3	—	11	10.6	9.6	4.8	3.9	—
5	—	17.5	16.7	15.2	7.6	6.1	—
7½	—	25.3	24.2	22	11	9	—
10	—	32.2	30.8	28	14	11	—
15	—	48.3	46.2	42	21	17	—
20	—	62.1	59.4	54	27	22	—
25	—	78.2	74.8	68	34	27	—
30	—	92	88	80	40	32	—
40	—	120	114	104	52	41	—
50	—	150	143	130	65	52	—
60	—	177	169	154	77	62	16
75	—	221	211	192	96	77	20
100	—	285	273	248	124	99	26
125	—	359	343	312	156	125	31
150	—	414	396	360	180	144	37
200	—	552	528	480	240	192	49
250	—	—	—	—	302	242	60
300	—	—	—	—	361	289	72
350	—	—	—	—	414	336	83
400	—	—	—	—	477	382	95
450	—	—	—	—	515	412	103
500	—	—	—	—	590	472	118

Synchronous unity-power-factor motors take the separate section of Table 430.250 (not reproduced here); at 90% and 80% power factor its figures are multiplied by 1.1 and 1.25. Wound-rotor and squirrel-cage share this table.

Single-phase motors

NEC 430.248

Full-load current in amperes by horsepower and rated motor voltage for single-phase AC motors (values per NEC Table 430.248). Currents are permitted for system voltage ranges 110–120 and 220–240 V.
HP	115 V	200 V	208 V	230 V
1/6	4.4	2.5	2.4	2.2
1/4	5.8	3.3	3.2	2.9
1/3	7.2	4.1	4	3.6
1/2	9.8	5.6	5.4	4.9
3/4	13.8	7.9	7.6	6.9
1	16	9.2	8.8	8
1½	20	11.5	11	10
2	24	13.8	13.2	12
3	34	19.6	18.7	17
5	56	32.2	30.8	28
7½	80	46	44	40
10	100	57.5	55	50

Note the clean halving: the 115 V column is exactly twice the 230 V column — same horsepower, half the voltage, double the current.

Table value vs. nameplate — the rule that trips people up

NEC 430.6(A)(1) splits motor sizing down the middle: the table values here determine the branch-circuit conductors (125% of FLC per 430.22), the short-circuit and ground-fault protection (430.52), the feeder calculations (430.24), and the disconnect — while the nameplate current sets only the overload protection (430.32). The logic: wiring sized from the standard table doesn't need to change when a motor is replaced with another of the same rating, but the overload device protects the actual winding installed. The motor FLA calculator runs the same table values with the 430.22 conductor minimum computed for you.

Reading the columns

Column voltages are rated motor voltages — read 460 V for a 480 V system, 230 V for 240, 115 V for 120 — and the highlighted 460 V column is where most industrial three-phase work lives. The values assume normal-torque motors at usual belted speeds; high-torque, multispeed, or inverter-duty machines can draw differently, which is one more reason overloads come from the nameplate. Once you have the FLC, the 125% conductor minimum lands on the wire ampacity chart — and remember motor circuits are the classic case where the breaker can legally be far larger than the conductor ampacity, because the overload relay is doing the protecting.

Common questions

What is the full-load current of a 10 HP, 460 V three-phase motor?

14 amperes per Table 430.250 — and that table value, not the nameplate, is what NEC 430.6(A)(1) requires for sizing the branch-circuit conductors (125% of 14 A = 17.5 A minimum ampacity per 430.22) and the short-circuit device. The nameplate current is used for one thing: setting the overload protection.

Why does the chart say 460 V when my system is 480 V?

The columns are rated MOTOR voltages — motors are wound for 460 V on a 480 V system, 230 V on 240, 115 V on 120. The table says its currents are permitted for the matching system-voltage ranges (440–480, 220–240, 110–120, 550–600), so a 480 V system reads the 460 V column. There is no separate 480 V column to look for.

My motor nameplate says a different FLA than the table — which one wins?

Both, for different jobs. Conductors, short-circuit/ground-fault protection, and disconnect sizing use the TABLE value (430.6(A)(1)) precisely so the wiring doesn’t change every time a motor is swapped for one with a slightly different nameplate. Overload protection (430.32) is sized from the NAMEPLATE, because it protects that specific winding. Using the nameplate for conductors is the classic plan-review red flag.

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