Asked by: Kiriam Kuehner
home and garden smart home

Do hard wired smoke detectors need a dedicated circuit?

Last Updated: 19th March, 2020

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A smoke detector does not need to be on a dedicated circuit in most instances, but builders should consult local building codes to check any applicable regulations.

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Thereof, are hard wired smoke detectors on a breaker?

If, by “hard wired” you refer to the type that is connected to the mains (with a backup battery in the smoke alarm), then yes — unless you enjoy running the risk of electrocution. However, if it's a detector connected to a fire alarm control panel the answer is no.

One may also ask, why are some smoke detectors hard wired? Because hardwired smoke alarms are connected to the power supply, they will sound indefinitely until they are turned off. They often have battery backups to ensure they continue in the event the power supply is cut as well.

Similarly, you may ask, are all smoke detectors on the same breaker?

Assuming they were installed correctly, are the 6 identical smoke detectors in my house on the same circuit? Normally yes, but it doesn't necessarily have to be that way. If they're the newer interconnect then it's easier to simply loop one line throughout the house (people almost always take the easy way out).

Why does my hardwired smoke detector keep going off?

Electrical Power Surges. A change in the electrical current to the wired smoke alarm will cause the smoke alarm sound to go off when there is not smoke in the air. A loose wire in the smoke detector can also cause it to go off as the electrical current is cut off and then restored to the alarm.

Related Question Answers

Baboucarr Yagodin

Professional

How do you turn off a hardwired smoke detector?

To reset a hardwired unit with a battery backup, perform the following steps:
  1. Turn off the power to the smoke alarm at the circuit breaker.
  2. Remove the smoke alarm from the mounting bracket and disconnect the power.
  3. Remove the battery (for a sealed-battery model, see Battery Settings for a 10-Year Alarm to learn more).

Aleksej Ialacci

Professional

How do you disconnect a hardwired smoke detector?

The steps are pretty simple:
  1. Turn off the power.
  2. Give your smoke alarm a twist to loosen it.
  3. Disconnect your smoke alarm from the wiring harness.
  4. Loosen the screws that hold the mounting bracket in place.
  5. Remove the mounting bracket.
  6. Disconnect the old wiring harness from the existing wires.

Mathew Kerinnes

Explainer

How do you reset a hardwired smoke detector?

Locate the reset button on the surface of the smoke detector. Hold it for 15–20 seconds and then release. Wait a couple of minutes and listen for the chirping noise again.

Ghazala Vasumati

Explainer

How do you wire a hardwired smoke detector?

Screw the new mounting plate to the junction box and connect the wires. Plug the harness into the new alarm, stuff the wires into the box and mount the alarm on the plate. If the smoke alarms in your house are 10 years old or more, it's time to replace them. To get started, remove each alarm from its mounting plate.

Bhrigu Goieneta

Pundit

Can I replace a hardwired smoke detector with a battery operated one?

If your home was built after 1986, it will have at least one hard wired smoke alarm connected directly to your electrical panel. It is not acceptable to replace a hard wired alarm with one that is battery operated. A home must maintain at least the same level of protection as originally required. It is the law.

Hafed Capllonch

Pundit

Nazario Chuhlomsky

Pundit

How many amps do smoke detectors use?

These devices are typically connected to a 120-volt, single-phase, 15- and 20-ampere branch circuit and include battery backup within the smoke alarm.

Lorilee Brasa

Pundit

Are smoke alarms wired into lighting circuit?

(Smoke detectors are usually wired to the lighting circuit, so turn this off at the switchboard). The alarm should sound indicating the battery condition is acceptable. If the unit fails to respond, the battery should be replaced without delay. From time to time the smoke alarm battery must be replaced with a new one.

Iver Boeckenholt

Teacher

Do smoke detectors have to be wired in series?

Hard-wired smoke detectors are connected in a series to provide a warning to every part of a home or building. Once one of the alarms goes off, the others follow. These detectors are connected to a power source all the time to ensure maximum protection.

Al Alberjon

Teacher

Where is the best place to put smoke detectors?

Smoke detectors should be installed on every level of your home to detect rising smoke from a fire. They should be placed inside or directly outside of each bedroom and common areas, and in laundry rooms and kitchens where fires can originate.

Boyan Ayegui

Teacher

What is code for residential smoke detectors?

For many years NFPA 72, National Fire Alarm and Signaling Code, has required as a minimum that smoke alarms be installed inside every sleep room (even for existing homes) in addition to requiring them outside each sleeping area and on every level of the home. (Additional smoke alarms are required for larger homes.)

Jaden Haze

Teacher

Can smoke detectors share a circuit?

Smoke alarm manufacturers require all interconnected devices to be powered from the same branch circuit. Section 210.12(B) of 2002 National Electrical Code (NEC) now requires the entire branch circuit supplying outlets in a dwelling unit bedroom to be protected by an arc fault circuit interrupter (AFCI) device.

Hilario Ardisana

Reviewer

How do you turn off an electric smoke alarm?

Take the smoke detector off its mounting bracket on the ceiling and disconnect the power cable plugged to the smoke detector. Take out its battery, then press the “Test” button holding it down for 15 seconds. An alarm will sound for a short time, then the alarm will silence.

Doa Vives

Reviewer

Do I need an electrician to replace hardwired smoke detectors?

They are hard-wired into our electrical system, but that doesn't mean you need an electrician to replace them. Modern hard-wired smoke detectors don't have wires in the back that need to be connected to loose wires in the ceiling.

Mateos Jurca

Reviewer

Will a hard wired smoke detector work without a battery?

Smoke Alarm Power Sources
Without the battery, neither of these units have the power to go off. Hardwired alarms often have a battery backup just in case the electrical power goes out. If you take the battery out of one of these units and your power goes out, the alarm will fail to sound and warn you of the danger.

Weiyan Eufemia

Reviewer

Eliza Gurke

Supporter

Why is my hard wired smoke detector beeping no battery?

As annoying as a smoke detector beeping can be, the most common cause is a low battery—a problem you can remedy without any hassle. It doesn't matter whether the alarm runs entirely on batteries or is hardwired and has a battery backup—either way, you're going to hear chirping when the battery goes dead.

Nydia Basarte

Supporter

Which is better hard wired or battery smoke detector?

Battery-powered smoke alarms are easier to install. While more work is required to install them, hardwired smoke alarms can be interconnected, meaning if one smoke alarm is activated, it will engage all other alarms in your home.

Alana Mengel

Supporter

Do all hard wired smoke detectors have batteries?

But nearly all smoke detectors, including those that run on household current, do contain a battery. Detectors that are hard-wired to the home's electrical system use this battery to provide backup power in case a fire knocks out the house's electrical power.