Electrical / Electronics
Historical underground three-core cable ampacity
Historical 1000 V cable data from a 1938 publication, for educational and comparative use only.
Related calculators
Manual three-phase cable sizing check
Checks a balanced three-phase system with manually provided Iz, protective-device and voltage-drop data.
Three-phase selection from user table
Selects the smallest entered section for a simplified balanced three-phase system.
Historical insulated-copper ampacity
Historical data from a 1938 publication. Exact Iz lookup for educational and comparative use only.
Wire resistance
Calculates theoretical wire resistance from resistivity, length and cross-sectional area.
Theoretical three-phase voltage drop
Calculates simplified voltage drop in a balanced three-phase system from per-length parameters.
Three-phase voltage drop from resistivity
Helper calculation for simplified three-phase voltage drop from resistivity and area; it does not replace standards-based calculations.