Input values explained
- Prąd
- Enter the expected operating current, not a fuse rating. Motors and electronic power supplies may draw much higher starting or peak currents.
- Cable length
- Enter the one-way distance from supply point to load. The required return path is already represented by the selected formula.
- Napięcie
- Enter the line-to-line voltage between two phases. This is commonly 400 V in low-voltage systems; 230 V is not the correct input here.
- Moc factor cos φ
- cos φ is the ratio of active to apparent power. It is close to 1 for resistive heating loads; use the data-sheet value for motors and transformers.
- Permitted voltage drop
- This percentage limits the calculated voltage loss. It is a design assumption and must suit the circuit and applicable requirements.
- Conductivity κ
- κ is the calculation value for the conductor material. Common approximations are 58 for copper and 37 for aluminium; heating increases actual resistance.