Hey bud great video. Iam an HVAC tech and need to replace System Sensor D4120 it looks like it will be wire for wire. My question is I will be notifying the monitoring company to put the fire system on test, what is the best way to disconnect the alarm and supervisory wire so I don’t short anything out. Turn power of at control panel? Will it start up once I turn the power back on? I will also turn off the breaker that is providing 120 volts to the detector . Thanks my knowledge of fire alarm is limited.
AC UNIT IS STAND ALONE (NO FIRE ALARM AND BMS); NEED TO USE DUCT SMOKE DETECTOR AND SOUNDER. UNIT HAS TO SHUT OFF AUTOMATIC IN CASE OF FIRE. SUGGEST ME HOW TO CONNECT IT.
I know this video is quite old but I hope to hear back from you. What is your opinion on using a mini monitor module and resistor in each detector? Also what is your opinion on getting your 24V from the hvac equipment instead of the panel?
It is typical to see an addressable monitor module at each duct detector. This video was more for the techs that struggle understanding how to properly wire multiple units with supervision on one circuit. I do not recommend having the HVAC contractor provide the power. These units like other 4-wire detectors are reset upon temp loss of power. This is why we always use resettable power. If there is an alarm, you simply press reset at the FACU which drops power and resets the unit. If you have the unit powered by the HVAC contractor, you will need to get up to the unit to press the reset button every time there is an alarm.
Makes sense, I worked with a cheap guy who liked to to use 1 module for multiple detectors, I worked with a lazy guy who liked to let the hvac guy power the detectors, but I have always personally liked to run power from the panel and have a module at each detector.
I have 5 RTU’S each with one induct smoke detector in the R.A. How can i interlock the smoke detectors to stop all units?, when one smoke detector its trip.... can you give me an idea, or what brand or module to use. Thank you
You will have to run the trouble contacts in series. One conductor runs in series through the trouble contacts. At the last device, the other conductor runs all the way back (this conductor can just be wire nutted at each device to make it easier)
99% of the time, I find that the original F/A installer never runs his EOL and jumper through the supervisory contacts. They land their FA circuit and strap it out with an EOL. 🥴
