Skip to main content
Speclore

Electric Wire Voltage Drop

Reference data and engineering information about electric wire voltage drop for electrical applications.

electricwirevoltagedrop

Overview

Engineering reference data for Electric Wire Voltage Drop in electrical engineering.

Key Formulas

Ohm's Law

V=IRV = IR

Voltage = Current × Resistance.

Power

P=VI=I2R=V2/RP = VI = I^2R = V^2/R

Electrical power.

Energy

E=PtE = Pt

Energy = Power × Time.

Variables

SymbolDescriptionUnit
VVVoltageV
IICurrentA
RRResistanceΩ
PPPowerW

Voltage Drop Specifications for Common Systems

For 240V and 120V single-phase systems, the following table outlines the maximum wire length for a 2% voltage drop across different wire gauges.

11 rows
Maximum wire length (in feet) for a 2% voltage drop in 240V and 120V single-phase AC systems at 100% power factor.
Wire Gauge (AWG)
Max Length (240V, 2% drop)(ft)
Max Length (120V, 2% drop)(ft)
3/0730182
2/0580145
1/0460115
136591
229072
418045
611529
87218
104511
12297
14184.5

Source: engineeringtoolbox.com

Wire Gauge Converter: AWG to Square Millimeters

The American Wire Gauge (AWG) system can be converted to metric cross-sectional area (square millimeters) for international compatibility. The following table provides common conversions.

13 rows
Approximate conversion between American Wire Gauge (AWG) and cross-sectional area in square millimeters (mm²).
AWG
Cross-Sectional Area(mm²)
4/0107.2
3/085
2/067.4
1/053.5
142.4
233.6
421.2
613.3
88.37
105.26
123.31
142.08
161.31

Source: engineeringtoolbox.com

Interactive Charts

240 120 volt wire length and voltage drop

References