⚡ Cu ρ (75°C): 0.0214 Ω·mm²/m 🔌 NEC / IEC Standards: NFPA 70 & IEC 60364 🇺🇸 US Grid Avg: $0.175/kWh 🇩🇪 DE Grid Avg: €0.345/kWh 🇸🇪 SE Elpris: 1.54 SEK/kWh 🇳🇴 NO Strøm: 1.17 NOK/kWh 🔩 Copper Ref: $9,650/t (2026-10-24)
🏭 Industrial Electrical Conversion · Three-Phase & Single-Phase

40 kW to Amps at 415V Three-Phase AC (UK / AU)

Exact current (Amps), real power (kW), apparent power (kVA), mechanical horsepower (HP), breaker rating, and conductor size for 40 kW on a 415V Three-Phase AC (UK / AU) circuit.

Line Current (0.85 PF)65.47 AAt 1.0 PF: 55.65 A
Active / Apparent Power40.0 kW47.06 kVA · 24.79 kVAR
Recommended Breaker90 A (NEC)70 A (IEC Nominal)
Recommended Copper Wire4 AWGIEC Metric: 16 mm²

Engineering Breakdown for 40 kW at 415V

Input Rating40 kW (415V Three-Phase AC (UK / AU))
Amperage at 0.85 Power Factor (Industrial Motor/Transformer)65.47 Amps
Amperage at 1.00 Power Factor (Resistive Load)55.65 Amps
Real Power (kW / Watts)40.0 kW (40,000 W)
Apparent Power (kVA) & Reactive Power (kVAR)47.06 kVA / 24.79 kVAR
Equivalent Mechanical Horsepower (HP)53.64 HP
NEC 125% Continuous Circuit Breaker90 A
Minimum Copper Conductor (100 ft / 30 m, ≤3% Drop)4 AWG (NEC) / 16 mm² (IEC)

Frequently Asked Questions

How many amps is 40 kW at 415V (3-Phase)?

At 415V Three-Phase AC (UK / AU), 40 kW equals 65.47 Amps at an industrial power factor of 0.85 (or 55.65 Amps at unity power factor 1.0).

What size breaker and wire is needed for 40 kW at 415V?

For 65.47A continuous load, NEC requires a 125% rated breaker of 90A with 4 AWG copper conductors, while IEC standard sizing uses a 70A breaker with 16 mm² copper cable.

Other Power Ratings & Voltages

5 kW at 415V (3P)10 kW at 415V (3P)15 kW at 415V (3P)20 kW at 415V (3P)25 kW at 415V (3P)30 kW at 415V (3P)45 kW at 415V (3P)50 kW at 415V (3P)75 kW at 415V (3P)100 kW at 415V (3P)150 kW at 415V (3P)200 kW at 415V (3P)250 kW at 415V (3P)500 kW at 415V (3P)40 kW at 120V Single-Phase AC40 kW at 208V Single-Phase AC40 kW at 230V Single-Phase AC (IEC)40 kW at 240V Single-Phase AC (NEC)40 kW at 208V Three-Phase AC40 kW at 230V Three-Phase AC40 kW at 400V Three-Phase AC (IEC Europe)40 kW at 480V Three-Phase AC (US Industrial)40 kW at 600V Three-Phase AC (Canada / Heavy)40 kW at 24V DC Direct Current40 kW at 48V DC Battery / Telecom Bus