Cable cross-section
by power and length: allowable current (PUE) + voltage drop + breaker rating
Parameters
Result
Recommended section (copper)
4 mm²
voltage drop 2,38% (limit ≤ 5%)
Operating current23,90 A
Min. by current4 мм² (28 A)
Breaker25 A
Currents are for copper VVG in concealed runs (chase/conduit): 1.5 mm²→15 A, 2.5→21, 4→28, 6→36, 10→50. Open runs allow more, aluminium less (≈0.77× copper). The breaker must exceed operating current but not the cable's rating. Always use a 30 mA RCD for socket/bathroom circuits.
About Cable cross-section
Cable cross-section — by power and length: allowable current (PUE) + voltage drop + breaker rating. build: . Use our tools without registration or installing software. All calculations happen in your browser — your data is never sent to a server.