How many amps does a 5 hp motor draw?

15.2 amps on three-phase 230V, or 7.6 amps at 460V. On single-phase 230V the same 5 hp draws 28 amps, close to double.

What does FLA mean on a motor?

Full-load amps, the current drawn when the motor delivers its rated output at rated voltage. It is a running figure and does not describe the much larger inrush at startup.

Should I use the nameplate amps or the NEC table?

NEC 430.6(A) requires the table values for sizing conductors and branch-circuit protection. Use the nameplate current for setting the overload relay, which protects the motor itself rather than the wiring.

Why does starting current matter?

A direct-on-line motor draws six to eight times its full-load current for a second or two at startup. A breaker sized to the running current would trip every time, which is why motor circuits use time-delay devices sized well above the conductor ampacity.

How do I convert horsepower to amps by hand?

For three phase, amps equal HP times 746, divided by 1.732 times voltage times efficiency times power factor. Using 0.88 efficiency and 0.85 power factor gets you close to the published table values.

Motor HP to Amps Chart

Author: Emma Clarke, Reference Desk3 min readReviewed 16 August 2026

Use the NEC full-load current tables, not the nameplate, to size conductors and overload protection. A 5 hp three-phase motor draws 15.2 amps at 230V and 7.6 amps at 460V. A 5 hp single-phase motor draws 28 amps at 230V, roughly double, which is why single phase gets expensive above a few horsepower.

Electrical. Based on NEC Table 430.248, NEC Table 430.250, NEC 430.6(A).

Three phase motor full load amps

These are the NEC Table 430.250 figures for three-phase induction motors. NEC 430.6(A) requires you to use these values rather than the motor nameplate when sizing conductors and branch-circuit protection, because the tables are deliberately conservative.

The nameplate current is still what you use for setting the overload relay, which protects the specific motor rather than the wiring.

Full-load current in amps, three-phase induction motors, NEC Table 430.250.
HP	208 V	230 V	460 V	575 V
1	4.6	4.2	2.1	1.7
2	7.5	6.8	3.4	2.7
3	10.6	9.6	4.8	3.9
5	16.7	15.2	7.6	6.1
7.5	24.2	22	11	9
10	30.8	28	14	11
15	46.2	42	21	17
20	59.4	54	27	22
25	74.8	68	34	27
30	88	80	40	32
40	114	104	52	41
50	143	130	65	52

Single phase motor amps

Single-phase motors draw far more current for the same output, because the power is delivered in one alternating supply rather than three overlapping ones. That is the practical reason workshops move to three phase somewhere around 5 to 7.5 hp.

Full-load current in amps, single-phase motors, NEC Table 430.248.
HP	115 V	230 V
1/2	9.8	4.9
3/4	13.8	6.9
1	16	8
1 1/2	20	10
2	24	12
3	34	17
5	56	28
7 1/2	80	40
10	100	50

What FLA means

FLA is full-load amps: the current the motor draws when it is delivering its rated output at rated voltage. It is a steady-state figure and says nothing about starting.

Starting current is a different number entirely. A direct-on-line induction motor pulls six to eight times FLA for the first second or two, which is why motor circuits use time-delay protection and why the breaker is sized well above the conductor ampacity under NEC 430.52.

To calculate rather than look up, three-phase amps equal horsepower times 746, divided by the product of 1.732, voltage, efficiency and power factor. At a typical 0.88 efficiency and 0.85 power factor the table values fall out closely.

Emma ClarkeReference Desk

Emma looks after the reference charts and calculators. Every figure is copied from the named standard on the page rather than generated, and each page shows the date it was last checked. When a value looks wrong, the standard wins and the page gets fixed.

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