⚡ 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)
⚡ IEC 60364-5-52 · DIN VDE · NEK 400 · SS 436 40 00

20 Amp Cable Size at 30 Meters (24V DC (Off-Grid Solar / Industrial Control))

IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 20 A over 30 m (98.4 ft).

Copper Cable (≤3% Drop)50 mm²Drop: 0.51V (2.14%)
Aluminum Cable (≤3% Drop)70 mm²Drop: 0.61V (2.52%)
Voltage at Load23.5 VLine Loss: 10.3 W
Max Power & Breaker0.48 kW20A MCB/MCCB

IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 20A at 30m

Cross-Section (mm²)Cu AmpacityAl Ampacity Cu Voltage DropLoad VoltageAl Voltage DropPower LossStatus
1.5 mm²16 A12 A17.12 V (71.33%)6.9 V28.24 V (117.67%)342.4 WDrop High
2.5 mm²24 A18 A10.27 V (42.8%)13.7 V16.94 V (70.6%)205.4 WDrop High
4 mm²32 A25 A6.42 V (26.75%)17.6 V10.59 V (44.12%)128.4 WDrop High
6 mm²41 A32 A4.28 V (17.83%)19.7 V7.06 V (29.42%)85.6 WDrop High
10 mm²57 A44 A2.57 V (10.7%)21.4 V4.24 V (17.65%)51.4 WDrop High
16 mm²76 A59 A1.6 V (6.69%)22.4 V2.65 V (11.03%)32.1 WDrop High
25 mm²101 A78 A1.03 V (4.28%)23.0 V1.69 V (7.06%)20.5 W~ ≤5%
35 mm²125 A97 A0.73 V (3.06%)23.3 V1.21 V (5.04%)14.7 W~ ≤5%
50 mm²151 A118 A0.51 V (2.14%)23.5 V0.85 V (3.53%)10.3 W✓ OK (≤3%)
70 mm²192 A150 A0.37 V (1.53%)23.6 V0.61 V (2.52%)7.3 W✓ OK (≤3%)
95 mm²232 A181 A0.27 V (1.13%)23.7 V0.45 V (1.86%)5.4 W✓ OK (≤3%)
120 mm²269 A210 A0.21 V (0.89%)23.8 V0.35 V (1.47%)4.3 W✓ OK (≤3%)
150 mm²309 A241 A0.17 V (0.71%)23.8 V0.28 V (1.18%)3.4 W✓ OK (≤3%)
185 mm²353 A275 A0.14 V (0.58%)23.9 V0.23 V (0.95%)2.8 W✓ OK (≤3%)
240 mm²415 A324 A0.11 V (0.45%)23.9 V0.18 V (0.74%)2.1 W✓ OK (≤3%)
300 mm²477 A372 A0.09 V (0.36%)23.9 V0.14 V (0.59%)1.7 W✓ OK (≤3%)
400 mm²570 A445 A0.06 V (0.27%)23.9 V0.11 V (0.44%)1.3 W✓ OK (≤3%)

FAQ — 20 Amp Cable Size at 30 Meters (24V DC (Off-Grid Solar / Industrial Control))

What mm² cable size is required for 20A at 30 meters (24V)?

According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 50 mm² copper cable for 20A over 30m at 24V (voltage drop: 0.51V or 2.14%).

What is the power capacity of 20A at 24V?

At unity power factor, 20A at 24V supports 0.48 kW with a standard 20A circuit breaker.