Describes requirements for construction, installation and operation of deliberately-operated alarm systems installed in locations where main interconnections are by physical conductors. Such systems have one or more deliberately-operated devices, one or more control equipments, one or more warning devices and power supply equipment. Applies to systems in which detectors are deliberately-operated devices (e.g. 'bandit alarm' systems) but not to systems which use mains wire or wire-free connections at a location other than for portable deliberately-operated devices within the system.