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Engineering ToolBox > Nema Starters
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.
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.