Determination of voltage drop
From Electrical Installation Guide
The impedance of circuit conductors is low but not negligible: when carrying load current there is a voltage drop between the origin of the circuit and the load terminals.
The correct operation of a load (a motor, lighting circuit, etc.) depends on the voltage at its terminals being maintained at a value close to its rated value.
It is necessary therefore to determine the circuit conductors such that at full-load current, the load terminal voltage is maintained within the limits required for correct performance.
This section deals with methods of determining voltage drops, in order to check that:
- They comply with the particular standards and regulations in force
- They can be tolerated by the load
- They satisfy the essential operational requirements