The recommended maximum total voltage drop on both feeders and branch circuits is ___ percent.

• A. 2
• B. 7.5
• C. 5
• D. 3

Answer: (C)

Voltage drop along conductors reduces the voltage that actually reaches outlets and loads. To keep devices operating properly and efficiently, a practical limit is set at about five percent for the total drop from the service to the farthest point. In design, this is typically split as roughly 2% for feeders and 3% for branch circuits, which adds up to 5% overall.

With a 120 V system, a 5% drop means about 6 volts lost, so the farthest outlet could see around 114 V. That level is generally acceptable for most loads, but if the drop is larger due to long runs or undersized conductors, performance issues can occur.