Fire case histories make an argument for requiring survivability of all fire alarm system circuits. A fire occurred in the London Apartments for the elderly in Delaware, Ohio, on March 12, 1994. Manual fire alarm boxes and corridor smoke detectors were connected to the building’s fire alarm system.
On a daily basis, we hear sounds and noise in our environment from a variety of sources, such as television, radio, household appliances and traffic. However, these everyday sounds are usually at a safe volume.