7.5 HP Motor — How Many Amps?
A 7.5 HP motor draws 40A at 240V (single phase) or 22A at 240V 3-phase. Wire: 6 AWG, Breaker: 50A. Common uses: Large shop motor, commercial equipment.
7.5 HP Motor Wiring Guide — NEC 430
Motor circuits must comply with NEC Article 430. Key requirements for a 7.5 HP motor:
NEC 430.22 — Conductor Sizing: Branch circuit conductors must carry at least 125% of the motor full-load amps (FLA). For this 7.5 HP motor at 240V: 40A × 1.25 = 50.0A minimum conductor ampacity. Use 6 AWG copper per NEC Table 310.16.
NEC 430.52 — Branch Circuit Protection: For inverse-time breakers, maximum overcurrent protection is 250% of FLA: 40A × 2.5 = 100A. Standard breaker: 50A.
NEC 430.32 — Overload Protection: Motor overload protection must not exceed 125% of motor nameplate FLA. A thermal overload relay or electronic overload is typically built into the motor starter.
Common applications: Large shop motor, commercial equipment. Use our Wire Size Calculator and Voltage Drop Calculator for exact conductor sizing.
HP to Amps Reference Table
| HP | 240V 1φ | 240V 3φ | Wire | Breaker |
|---|---|---|---|---|
| 1/2 HP | 4.9A | 2A | 14 AWG | 15A |
| 3/4 HP | 6.9A | 2.8A | 14 AWG | 15A |
| 1 HP | 8A | 3.6A | 12 AWG | 20A |
| 1.5 HP | 10A | 4.8A | 12 AWG | 20A |
| 2 HP | 12A | 5.6A | 10 AWG | 25A |
| 3 HP | 17A | 9.6A | 10 AWG | 30A |
| 5 HP | 28A | 15.2A | 8 AWG | 40A |
| 7.5 HP | 40A | 22A | 6 AWG | 50A |
| 10 HP | 50A | 28A | 6 AWG | 60A |
| 15 HP | 80A | 42A | 3 AWG | 100A |
| 20 HP | 100A | 54A | 1 AWG | 125A |
| 25 HP | 130A | 68A | 1/0 AWG | 150A |
| 30 HP | 150A | 80A | 2/0 AWG | 175A |
| 40 HP | 200A | 104A | 3/0 AWG | 250A |
| 50 HP | 250A | 130A | 4/0 AWG | 300A |
Disclaimer: Values from NEC Tables 430.248 and 430.250. Always check motor nameplate for actual FLA. Consult a licensed electrician.