NEMA Starter

NEMA electrical motor starters refer to a standardized rating system for the electrical performance of the most common style of American-built motor starters. NEMA starters are rated by size: 00, 0, 1, 2, 3, 4, 5, 6 and 7.

Polyphase Motors

Maximum electrical motor horsepower for different NEMA starters for three phase motors can be found in the table below:

Maximum Horsepower (hp)
NEMA Size	NEMA Continuous Amp Rating (Amp)	Full Voltage Starting			Part Winding Starting			Wye Delta Starting
		200V	230V	460V 575V	200V	230V	460V 575V	200V	230V	460V 575V
00	9	1.5	1.5	2
0	18	3	3	5
1	27	7.5	7.5	10	10	10	15	10	10	15
2	45	10	15	25	20	25	40	20	25	40
3	90	25	30	50	40	50	75	40	50	75
4	135	40	50	100	75	75	150	60	75	150
5	270	75	100	200	150	150	350	150	150	300
6	540	150	200	400		300	600	300	350	700
7	810		300	600		450	900	500	500	1,000

Ease of selection is a fundamental design advantage of a NEMA-style starter. To select a NEMA starter only horsepower and voltage are needed. NEMA starters have interchangeable heater elements and makes NEMA starters attractive in projects where the motor specification is not known until the start-up date.

Single Phase Motors

Maximum horsepower, full voltage starting, two pole contactors, are indicated below:

Maximum Horsepower (hp)
NEMA Size	115 Volts	230 Volts
00	1.3	1
0	1	2
1	2	3
2	3	7.5
3	7.5	15