The 4 wires are for the connections on the smoke detector and there are 8 wires to the buildings.
Even though the description for the detector says “4 wire”, there are 8 wires that go to the smoke detector from the building wiring.
in other words, 4 Wires or 4 Pairs of Wires
To describe a four wire smoke detector, four wires is really a misnomer. Most four wire smoke detectors have 4 screw-terminal contacts, but if instead of the 4 screw-terminals there are wires, then there are 8 wires. That’s 4 pairs of wires.
A four wire smoke detector is just like a two wire smoke detector, except that it receives its power from an auxiliary power supply rather than the conventional Initiating Device Circuit. Both the two wire and the four wire smoke detector sense particles in the air and call the particles smoke.
When you get down to it, the four wire smoke detector is a lot like a conventional air duct smoke detector. There are 4 terminals – two terminals are to send alarms in on the zone and two of the terminals are to power the detector. Just like a conventional air duct smoke detector, 2 wires are used to get power for the smoke detector; just like a duct detector 2 wires are normally open alarm relay contacts that connect to the zone circuit
If you’re needing a simple four wire smoke detector（or two wire smoke detector） then our products are the perfect fit. These smoke detectors are great for running all through the building to help prevent or alert to a huge fire disaster. These can be used on any 12 or 24 volt system and can match conventional fire alarm control panel.
welcome to contact us ！