We have always advocated wiring the smokes to a local lighting circuit. The thinking is that if the breaker trips, you'll know it. You may not know it if a dedicated smoke circuit trips. Example being ... residents are on vacation and a surge or short outage causes the breaker to trip. After a week or so the batteries are dead and the residents return unaware of the lack of protection. The question: (I have no access to NFPA 72) is this code or just something we have always done?
