- A value assigned to a circuit or system for classification purposes. Operation may actually be possible within a range, and the nominal voltage is often the midpoint of that range.
- A rated or named value, stating the available, input, or output voltage of a component, circuit, device, piece of equipment, or system, under specified conditions. For instance, the stated AC line voltages for a given locality may be 115/230, where the lower number is primarily for lighting and small appliances, and the larger number is for heating and large appliances. The actual values, or interval of values, may not coincide with these numbers. Also called nominal voltage rating, or rated voltage (1).