On the job I'm on, the smoke detectors in the HVAC ducts are powered from the convienience outlets in the RTU's. I don't have a copy of NFPA 72, but this doesn't seem like a good idea to me. Should any one trip or turn off a breaker for these outlets there is an alarm initiated. Any info will be appreciated.
I can't site a specific code but the equipment my company manufactures requires the entire smoke circuit to be operated off of a dedicated fire circuit. That includes the fire/smoke detectors, CO detectors, smoke purge and blower interlocks. If there is an outlet somebody is going to plug a drill into it eventually and depending on the fuse or circuit breaker size pop the circuit.
Edited out CO2 I must have been craving a soda.
NFPA 72 requires:
"Fire alarm systems shall be provided with at least two independent and reliable power supplies, one primary and one secondary." and:
"Connections to the light and power service shall be on a dedicated branch circuit." and:
"The OC device shall have a red marking, shall be accessible only to authorized personnel, and shall be identified as 'FIRE ALARM CIRCUIT CONTROL'."
Also, that would be CO detectors, not CO2.
would a CO2 detector be what they use to track gases that cause global warming? j/k
CO is what they're concerned with; carbon monoxide is much more deadly than carbon dioxide (although they're both bad news in the appropriate concentrations).
be sure the power source isn't gfi protected (760.21)