Motor Full-Load Current Calculator
Calculate Breaker, Contactor, Overload & Wiring Sizing
⚠️ Single-phase motors above 15 kW are uncommon. Consider 3-phase.
⚠️ Please fill required fields.
Motor Parameters
Enter power > 0
Voltage must be 100V or more
Full Load Amps
—
FLA rated current
Min Circuit Amps
—
MCA = FLA x 1.25
Overload Setting
—
NEC 430.32
Circuit Breaker
—
—
Calculation Summary
Power:—
Voltage:—
Phase:—
Power Factor:—
Efficiency:—
Service Factor:—
Frequency:—
Ambient:—
Enter parameters and click Calculate...
Circuit Breaker
MPCB/MCCB at 150% FLA (NEC 430.52 max 250%)
Schneider—
Siemens—
ABB—
Eaton—
Contactor AC-3
AC-3 rated. Next standard frame above FLA
Schneider—
Siemens—
ABB—
Eaton—
Thermal Overload
NEC 430.32: Set at 115% FLA (SF=1.0) or SF x FLA (SF>1.15)
Schneider—
Siemens—
ABB—
Eaton—
NEC / IEC References
- NEC 430.6: Use NEC Table FLA values for sizing
- NEC 430.22: Conductors at least 125% FLA
- NEC 430.32: Overload at most 125% FLA (SF=1.0) or SF x FLA
- NEC 430.52: Breaker standard 150% FLA, max 250%
- IEC 60947-4-1: Contactor AC-3 rated at least FLA
Cable Sizing (NEC 430.22)
—
Copper PVC 70C
MCA (125% FLA): —
Derating: None (40C)
Method: IEC 60364-5-52 Method C
Cu Cable Table PVC 70C
| mm2 | Amps | AWG |
|---|---|---|
| 1.5 | 15 | 16 |
| 2.5 | 21 | 14 |
| 4 | 28 | 12 |
| 6 | 36 | 10 |
| 10 | 50 | 8 |
| 16 | 66 | 6 |
| 25 | 84 | 4 |
| 35 | 104 | 2 |
| 50 | 125 | 1 |
| 70 | 160 | 2/0 |
| 95 | 194 | 3/0 |
| 120 | 225 | 4/0 |
| 150 | 260 | 300MCM |
| 185 | 297 | 350MCM |
| 240 | 346 | 500MCM |
| 300 | 400 | 600MCM |
IEC 60364-5-52 Method C PVC 70C single circuit
Cable Notes
- Sized by ampacity only. Verify voltage drop for runs over 30m
- Apply derating for ambient above 40C or grouped cables
- For VFD use shielded motor cable
- Confirm with NEC, IEC 60364, BS 7671
⚠️ Disclaimer: Estimation tool only. Verify results against motor nameplate and applicable codes (NEC/IEC/BS 7671) with a qualified engineer.
