Allen Tel Products GB33645-L1 Network Media Box Enclosure With 1 Telco 6 Line Circuit Module And 1 RJ31-X Security Alarm Jack

everybody my name is Kyle I I am a commercial what I'm gonna tell you today is the difference between Class A and Class B IDC wiring a fire alarm device needs to have three different signals it needs to have a normal signal a treble signal and an alarm signal I'm going to tell you how both B and a achieve all three of these signals Class B is one wire from the zone that goes to the device and it has an end-of-line resistor when the device is normal the panel sees the resistance value when the device shorts because it activates because of heat or smoke the alarm or the PLC's ashore when I cut one wire and the panel season open it sees a trophy Class B wiring one wire and resistor Class A wiring plugs one wire that goes out to the device and one wire that comes back to the panel there's no end-of-line resistor when the circuit is complete the panel can see all the way through the two wire