What is the maximum allowable voltage drop for branch circuits?

The maximum allowable voltage drop for branch circuits is 3%. This standard is generally accepted by the National Electrical Code (NEC) and is crucial for ensuring that electrical systems operate efficiently and safely. A voltage drop exceeding this percentage can lead to poor performance of electrical devices, increased risk of overheating, and potential safety hazards.

Voltage drop refers to the decrease in voltage that occurs as electrical energy travels through the wiring to reach its destination. A 3% drop is considered a practical limit, ensuring that sufficient voltage reaches the end devices to function properly while minimizing energy losses. This standard helps maintain the performance of lighting, appliances, and other devices that rely on adequate voltage levels.

In comparison, options suggesting a voltage drop of 1% or even higher percentages such as 5% and 10% would result in significant inefficiencies and operational issues, contradicting best practices for electrical installations. Maintaining a voltage drop within the recommended 3% helps to safeguard the integrity of the electrical system, optimize performance, and comply with safety regulations.