Banch Circuits

Branch Circuits

  • Definition: Conductors between the final overcurrent device (circuit breaker) and outlets.
  • Everything after circuit breaker is a branch circuit; before it is a feeder.
  • In residential settings, service feeds the panel; branch circuits are connected from it.
  • Subpanels: Service feeds the panel; feeder feeds the subpanel; branches from that.

Circuit Breakers & Protection

  • Circuit breakers provide protection; branch circuits have voltage limitations and GFI protection.
  • All regulations can be found in the code book under branch circuits (look in the index, not the table of contents).

Types of Conductors

  • Three basic types: Service, Feeder, Branching.
    • Service Conductors: From utility to service disconnect (house panel).
    • Feeder Conductors: Between service equipment and distribution (e.g., subpanels).
    • Branch Circuit Conductors: From overcurrent protection to the electrical outlets.

Relevant Code Articles

  • Service Conductors: Article 230 (Service Point to Disconnect).
  • Branch Circuits: Article 210.
  • Feeders: Article 215.

Branch Circuit Ratings

  • Rated according to the maximum rating of the overcurrent device; can be 10, 15, 20, 30, 40, 50 amps.
  • Circuit rating is not defined by conductor size but by breaker size.

Multi-Wire Branch Circuits

  • Definition: Consists of two or more ungrounded conductors sharing a neutral.
  • Must originate from the same panel and grouped together in the panel.
  • Special breakers (tie breakers) are needed to trip both circuits simultaneously for safety.

Nonlinear Loads

  • Nonlinear loads do not follow the current wave shape of the applied voltage; they can occur in electronic equipment.
  • Dedicated or oversized neutrals (super neutrals) are required to handle excess current from nonlinear loads.

Grounding and Ungrounded Conductors

  • Three functions in branch circuits: Ungrounded, Grounded, and Grounding conductor.
  • Grounding conductors: Identified as green, green/yellow stripes, or bare.
  • Grounded conductors are usually white or gray with continuous stripes for identification.