Input values explained
- Current type
- The current type determines whether the calculation uses factor 2 for outgoing and return conductors or √3 for balanced three-phase power.
- Conductor material
- Copper and aluminium have different conductivity. Aluminium generally requires a larger cross-section under otherwise equal conditions.
- Power in kilowatts
- Enter the electrical active power in kW. One kW equals 1,000 W; motor output power and electrical input power are not necessarily the same.
- Cable length
- Enter the one-way distance from supply point to load. The required return path is already represented by the selected formula.
- Voltage
- Match the voltage to the selected electrical system. Single-phase calculations use line-to-neutral voltage, while three-phase calculations use voltage between two line conductors.
- Power 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.