VAC is a unit of Alternating voltage, Volt Alternating Current. It is commonly used to represent the voltage in an AC circuit. In electrical engineering, AC voltage is usually measured in terms of VAC, which corresponds to DC voltage (VDC). The size of the VAC depends on the frequency and voltage of the power supply. For example, home appliances usually use 110VAC or 220VAC AC. The measurement of VAC is essential to ensure the safe operation of circuits and equipment, so engineers and technicians need to understand how to properly measure and handle VAC.
In VAC, V=volt (volt) AC= Alternating Current (alternating current) For example, 220VAC can be understood as an alternating voltage of 220 volts