But if you have AC-powered smoke detectors in your home and your home has been built in the last 10 years in the U.S., chances are they are wired together to intercommunicate. This sort of wiring guarantees that if one alarm in the house goes off, they all go off. The electrician runs the red wire from alarm to alarm to interconnect them. When any alarm detects a fire, it sends a 9-volt signal on the red wire. Any alarm that detects a 9-volt signal on the red wire will begin sounding its alarm immediately.
Most alarms can handle about a dozen units intercommunicating on the same red wire.
It's a very simple and a very effective system. Inc. All rights reserved.