Do Hard Wired Smoke Detectors Count As an Outlet on a Branch Circuit?

Outlets

• National electrical code defines an outlet as any point in the electrical wiring where the power is used. This includes receptacles, lights and any appliance that uses electrical power, whether it is wired directly to the house wiring, or connected with a corded plug to a receptacle. The definition further clarifies that a single fixture, even if it has more than one light or set of receptacle slots, counts as a single outlet.

Branch Circuits

• House wiring is made up of branch circuits. Power is distributed throughout the home via circuit breakers in the main service panel. Each circuit breaker controls a different branch circuit and the outlets on it. The maximum recommended number of outlets on a lighting or similar branch circuit is twelve. Some may have more than twelve if local code allows and the power requirements don't exceed the circuit breaker and wire capacity.

Smoke Detectors

• Local electrical codes may require a separate branch circuit specifically for hard-wired smoke detectors. This prevents the smoke detectors from losing power if another outlet causes a circuit breaker to trip.

  Smoke detectors use electrical power and that makes each hard-wired smoke detector on a branch circuit an outlet. Individually, the smoke detectors do not use much current and for this reason, more than 12 may be allowed on a branch circuit.

Building Codes

• Older homes are often fitted with battery-powered smoke detectors. Newer construction laws specified using hard-wired units with a battery backup. Most local jurisdictions now require that all the units in a home are interconnected with a third wire. If one unit sounds the alarm, all the units will respond with an alarm. This allows people sleeping in one room to hear an alarm that is detected in another room.