Special Features:

Used to monitor a single device or a zone of four-wire smoke detectors, manual fire stations, water flow devices, or other normally-open dry-contact devices. May also be used to monitor normally-open supervisory devices with special supervisory indication at the control panel.

Properties:

A grouping of two or more different types of electrical/electronic components mounted on a common mounting. it may include an assembly of electrical/electronic components mounted on multiple printed wiring board(s) mounted back to back, stacked, and the like. the item is generally a component of a subassembly and cannot be assigned a more definite item name. excludes items which may be identified as a subassembly. for an assembly of electrical/electronic components mounted on a single printed wiring board, see circuit card asseembly. do not use if a more specific name applies.