What is Voltage Drop
Voltage drop is defined as the amount of voltage loss that occurs through all or part of a circuit due to impedance. A common analogy used to explain voltage, current and voltage drop is a garden hose. … This condition causes the load to work harder with less voltage pushing the current.
Voltage drop Formula for DC/Single Phase:
Vdrop = I*R
I – flow of current
R – resistance of the circuit
Resistance of the wire = Resistivity of the material* Length/Cross-section of the cable
AWG to MM2 Chart

Example Problem:
How far can No. 6 copper wire be used to carry a load of 30 amperes at 240 volts and keep within 1% voltage drop?
