Service vs Feeder vs Branch Circuit Study Guide

Service, feeder, and branch-circuit terms describe different levels of an electrical distribution system. The exam-study skill is recognizing where each term sits in the hierarchy.

Use the system level as a clue before deciding which Code topic, formula, or study guide should be consulted next.

• Recognize service-level terminology near the supply and service equipment.
• Recognize feeder terminology between distribution points.
• Recognize branch-circuit terminology at the final circuit level.
• Use one-line position to help interpret the terminology.