Three fire hoses are connected to a fire hydrant. Each hose has a radius of 0.0200 m. Water enters thehydrant through an underground pipe of radius 0.0800 m. In this pipe, the water has a speed of 3.00 m/s.(a) How many kilograms of water are poured onto a fire in one hour? (b) Find the water speed in eachhose.
I really not sure, but, I think inside the house is one place. ;-) You could call your local Fire Department and they may say or even have a Brochure or number to call from there. I keep one by the Gas Furnace (It do CO2 also), Living Room close to the TV and Radon Detector in the Kitchen (All Hard Wired so not batteries). Not sure of the law, I just placed them where the most likely place of an Electrical Fire take place. Radon probably a joke as it was not there for years, so, the odds are slim it ever be there. It a gas like Natural Gas, if it not building up when the house is built I doubt it ever will (My Opinion).
Simple answer: they do not require a dedicated circuit, but they must not be on a switched branch. They often use dedicated circuits because detectors are now networked to sound all alarms in an occupancy if any one alarm senses heat or smoke. (Emergency lighting is normally dedicated) California is subject to NFPA and NEC at minimum, but being on the Left Coast things are added. (Search LA County Reference Standards Electrical). Smoke alarms need not be supplied by a dedicated circuit, but cannot be supplied from a switched circuit. A branch circuit which supplies power or light is acceptable before any switch. From Mike Holt (q.v.) From the Fire Alarm Code NFPA 72 For smoke detectors 11.6.3 AC Primary Power Source. The ac power source shall comply with the following conditions: (4) AC primary (main) power shall be supplied either from a dedicated branch circuit or the unswitched portion of a branch circuit also used for power and lighting. For fire alarm systems 4.4.1.4.1 Dedicated Branch Circuit. A dedicated branch circuit of one of the following shall supply primary power1) Commercial light and power(2) An engine-driven generator or equivalent in accordance with 4.4.1.9.2, where a person specifically trained in its operation is on duty at all times(3) An engine-driven generator or equivalent arranged for cogeneration with commercial light and power in accordance with 4.4.1.9.2, where a person specifically trained in its operation is on duty at all times
