Sizing and protection of conductors
From Electrical Installation Guide
Selection of cross-sectional-areas of cables is certainly one of the most important tasks of the design process of an electrical installation as this greatly influences:
- the selection of overcurrent protective devices,
- the voltage drop along these conductors
- and the estimation of the prospective short-circuit currents
This chapters details the different steps and methodologies for conductor sizing. And the specific recommendations for neutral and Protective Earth (PE) conductors sizing.
Chapter G - Contents
- Conductor sizing and protection
- Practical method for determining the smallest allowable cross-sectional area of circuit conductors
- Determination of voltage drop
- Short-circuit current
- Short-circuit current at the secondary terminals of a MV/LV distribution transformer
- 3-phase short-circuit current (Isc) at any point within a LV installation
- Isc at the receiving end of a feeder as a function of the Isc at its sending end
- Short-circuit current supplied by a generator or an inverter
- Particular cases of short-circuit current
- Protective earthing conductor (PE)
- The neutral conductor
- Worked example of cable calculation
