Skip to main content
Our Accessibility Statement

SA521CN-3ST Interconnected Smoke Alarm with Hardwire Adapter Included

SKU: SA521CN-3ST

The First Alert SA520 Interconnected Smoke Alarm with Hardwire Adapter Included allows you to create an interconnected fire alarm system without the hassle of rewiring. Use this smoke detector to replace an existing hardwired smoke alarm and then install additional First Alert wireless detectors for an interconnected safety network (additional detectors sold separately). This hardwired smoke and fire detector can connect and communicate with up to 18 compatible alarms, so when one is triggered, the entire system will sound. Equipped with battery backup, this smoke and fire alarm provides continuous protection during power outages.

  • When one alarm is triggered, all connected alarms will sound
  • Battery backup provides continuous detection during power outages
  • Hardwired smoke detector can communicate wirelessly with other compatible alarms to create a fire alarm system (additional alarms sold separately)
SA521CN-3ST Interconnected Smoke Alarm with Hardwire Adapter Included
SKU: SA521CN-3ST
Wireless Carbon Monoxide Alarm Lifestyle for CO511B SA511CN2-3ST SA521CN-3ST SC7010B SC7010BV SCO7CN

Product Overview

Create an Interconnected Fire Safety System

The First Alert Interconnected Smoke Alarm with Hardwire Adapter Included makes it easy to begin creating a safety network of detection. This detector is designed to replace an existing hardwired 120-volt alarm so you can add up to 18 First Alert wireless interconnected alarms - by connecting multiple wireless interconnected detectors, you can be alerted to danger on the other side of your house before the smoke from that area reaches you. When one detector sounds, all connected alarms in the system will sound simultaneously.

Hardwired Smoke Alarm

The interconnected smoke alarm is designed to easily replace most existing 120-volt hardwired detectors. Equipped with an easy adapter plug, there is no need to rewire when installing the fire alarm. Also, in case of power outages, the smoke detector has a battery backup feature designed to ensure continuous protection. A low-battery light and chirp will let you know when the AA batteries need to be replaced in the smoke detector.

Specifications

ModelSA520
TypeSmoke Alarm
Sensor TypePhotoelectric
Sensor InformationSmoke particles of varying number and size are produced in all fires. For maximum protection, use both ionization and photoelectric sensing technologies. Ionization alarms are generally more sensitive to fast flaming fires and photoelectric alarms are generally more sensitive to smoldering fires.
Power SourceHardwired
Number of Batteries2
Battery BackupYes
Backup Battery SizeAA
Wireless InterconnectivityYes
Sound Level85dB at 10 feet
Product Height2 in
Product Length5 in
Product Width5 in
Product Weight1 lb
FeaturesEnd-of-Life Warning, Battery Backup, Hardwire Interconnectivity, Hardwire Quick Connect Plug Included
UPC Number029054002440
Warranty10 Years Limited
View All

Resources

User Manual for SA520 Interconnected Smoke Alarm (English)

More Information on Ionization vs. Photoelectric Smoke Alarms