On September 15, 2018 at 22:58, Ernie Gilman said...
I don't get the need for this on a smoke alarm, but it's standard for burglar alarms: a thief can't bypass the alarm by either shorting together or opening wires.
The reason it is code and HAS to be done, is the same as a thief... but the thief in this case is fire. If the fire is burning somewhere that would compromise the fire wire (before the detector has a chance to go off), then the panel will still trip and alert everyone before they are all potentially killed.
