What is the maximum allowable voltage drop in a residential branch circuit?

The maximum allowable voltage drop in a residential branch circuit is critical for ensuring that electrical systems operate efficiently and safely. For branch circuits, the recommended limit is typically 3%. This ensures that appliances and devices receive sufficient voltage for proper operation. A voltage drop beyond this threshold can lead to poor performance, overheating, and potential equipment damage.

Additionally, for feeders, the maximum allowable voltage drop is generally 5%. This higher limit is acceptable since feeders supply power from the main service panel to various branch circuits and are rated to handle a broader range of load conditions.

Choosing the values of 3% for branch circuits and 5% for feeders aligns with industry standards, promoting reliable electrical performance and encouraging efficiency across the system. This rationale supports the importance of maintaining suitable voltage levels throughout the electrical infrastructure in residential settings.