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Smoke and CO alarm circuits playbook

Goal

Install smoke and CO alarm circuits with proper power, interconnection, and protection.

Inputs you must know before you start

  • Required alarm locations and types.
  • Circuit plan and panel capacity.
  • Interconnection method and listing requirements.
  • AFCI requirements for the project.

The path (in order)

  1. Identify required alarm locations and devices.
  2. Provide required power source and backup.
  3. Install interconnection wiring per listing.
  4. Apply AFCI requirements where required.
  5. Test alarms and document circuit labeling.

This is

A checklist for compliant alarm circuit installation in dwelling units.

This is not

A commercial fire alarm system design.

Inspection-ready checklist

  • Alarm locations verified.
  • Power and backup provided.
  • Interconnection tested.
  • AFCI compliance confirmed.
  • Circuits labeled.

Worked example

A dwelling uses hardwired interconnected smoke/CO alarms with AFCI-protected circuits. Alarms are tested and the circuit is labeled at the panel.

Cross references

  • Primary: 210.12, 760.41
  • Secondary: 110.3(B)