What is the minimum allowable voltage on a 120V branch circuit?

The minimum allowable voltage on a 120V branch circuit is 116.4V. This value is based on the National Electrical Code (NEC) which allows for a tolerance in voltage levels for nominal voltages. For a 120V circuit, a voltage that is below 116.4V may indicate a problem with the circuit, such as excessive voltage drop or equipment malfunction.

The rationale for setting this minimum threshold is to ensure that electrical devices operate within safe and efficient parameters. Many electrical devices are designed to work optimally at their nominal voltage, and a supply voltage falling below this minimum can lead to inefficient operation or cause damage to sensitive electronics.

This significance of maintaining the voltage above this level is crucial for the reliability and safety of electrical systems in entertainment venues and other applications. Understanding these voltage requirements helps technicians ensure compliance with safety standards while also preventing equipment failure resulting from inadequate voltage levels.