Smoke Alarms - Hardwired & Interconnecting
I want to retrofit my old house with hardwired interconnecting smoke alarms. I'd like to start of course in the basement where I have a dedicated old 12/2 metal conduit circuit that was used in the past but now has not home.
The smoke alarms have a red, white, and black wire. The red is used for interconnections. I was told the circuit for smoke alarms can't be protected by a ground fault interruptor. Now I understand the metal conduit from my 12/2 is the ground.
Does this mean I apply electric tape to the conduit before fastening it to the metal electric box to lose the ground fault interruption? This is all abstract to me what happens by cutting off the ground fault, or not...??? If someone can please explain I'll thank you in advance.
Also, to interconnect one smoke alarm to the next, can I use the ground (since it is not being used) of the 12/2 for the red to interconnect? Or, do I have to use a 12/3? Or, something else?
I don't know what else to ask...