Line voltage is the voltage existing in a cable or circuit, referring to the standard operating voltage supplied to equipment or distributed through a system.
Line voltage refers to the voltage carried by a circuit or cable as it supplies power to equipment. The term distinguishes the standard supply voltage from lower control or signal voltages, and it sets the insulation and safety requirements a cable must meet to carry it. Knowing the line voltage of a circuit is a starting point for selecting appropriate conductors and components.
In commercial and industrial systems, matching cable to the line voltage is essential for safe, reliable distribution. Equipment is designed to operate at specific line voltages, and the cable serving it must carry an adequate voltage rating and suitable insulation. Using cable rated for the application helps prevent insulation stress and supports dependable operation across the system the cable serves.
Because equipment is built to tolerate only a limited range around its rated line voltage, excessive drop or rise can impair performance or shorten service life, which is why conductors are sized to keep the delivered voltage within acceptable limits.
Confirming the delivered voltage at the equipment, not just at the source, is part of ensuring a circuit performs as intended end to end.
At Windy City Wire, the focus on properly rated low-voltage and control cable connects directly to how systems handle line voltage and the lower voltages used for signal and control. Supplying cable matched to the voltage of each circuit helps commercial facilities distribute power safely and reliably.