Voltage Drop


Definition of Voltage Drop

Voltage drop refers to the decrease in voltage that occurs when an electrical current flows through a wire or circuit.

It’s caused by the resistance of a wire or conductor, which is the opposition an electric current encounters as it tries to pass through. Resistance causes some energy loss in the form of heat as the current flows through the circuit.

voltage drop illustration on a circuit

In ideal conditions, the wires and conductors on a circuit should not use any energy. If they do, the electric current is reduced, and the electrical device powered, such as a light bulb, doesn't get enough power to operate.

With a 240-volt system, such as the one found in homes, a 12-volt voltage drop might go unnoticed. However, a 1 V voltage drop on a 12 or 24-volt system will significantly affect the brightness and performance of a lighting system.

(Keep in mind that marine vessels typically use a 12-volt or 24-volt electrical system to power lighting.)

Voltage drop can be minimized by using thicker cable and shortening the distance between the low voltage transformer and the light fixtures.

The amount of voltage lost increases with the length of a wire but decreases as the cross-sectional area (mm2) increases.

Synonyms: volt drop

Related Terms for Voltage Drop