WireTheSunSolar planner- 2.5 mm²
- 14 AWG
- 25 A
- Breaker
- 4.5%
- Voltage drop
- 17 m
- 3-core cable
Cable size calculator
Amps, distance and supply in. Cable size, breaker, voltage drop and which cable to buy out.
How the cable runs
Use at least2.5 mm²14 AWG
Breaker25 A
Voltage drop4.5% · 5.4 V
Current20 A
Cable carries up to27 A
Heat decides this size: it carries the breaker current without overheating, and the voltage drop is fine.
Cores
3 cores: line, neutral and earth
Which cable
Twin & Earth 6242Y (UK) or NYM-J (Europe)
Fixed wiring clipped to walls indoors.
H07RN-F (rubber, flexible)
Machines, workshops and anything that moves or vibrates.
- Several circuits bundled together carry less each: allow for grouping (IEC 60364-5-52 Table B.52.17).
- Check the earth fault loop impedance and the RCD protection required by your local rules.
Guidance based on IEC 60364-5-52 for copper cables. Always check against your local rules (BS 7671, NEC, NF C 15-100, RTIEBT…) and the cable maker’s data.