GNW12 base for optical smoke detectors

GNW12 base is built as a single electronic module set in a plastic cage fit to be installed on a ceiling using, for example, screws in a distance of 90mm. The device has mounting brackets that enable OSD23/03 smoke detector to be connected to the base as well as a connector to screw a terminal strip of a fire watch line. Contacts of the alarm relay (3,4,5) and those of the TAMPER sabotage micro switch (6,7) are isolated from the module’s electronic part.
The cage has a mechanical locking (in a form of a plastic clasp lock), that prevents OSD23/03 detector from an unauthorized removal from the base (to remove it, a special key is required.) Breaking off a plastic clasp lock before installing the detector in the base inactivates this locking.

Terminals (1,2): +, – - power supply line
Terminals (3,4,5) - three contacts of the relay (4 – relay's armature.)
The base’s electric circuit, on its soldering side, has a NC-NO switch, realized with a drop of tin. To switch, a soldering iron is required.
The tin jumper in NC position (factory condition):
- when there is no power supply, contacts 4 and 5 are shorted
- when there is power supply and no alarm (stand-by position), contacts 3 and 4 are shorted
- when there is power supply and alarm, contacts 4 and 5 are shorted
The tin jumper in NO position:
- when there is no power supply, contacts 4 and 5 are shorted
- when there is power supply and no alarm (stand-by position), contacts 4 and 5 are shorted
- when there is power supply and alarm, contacts 3 and 4 are shorted.
Terminals (6,7): TAMP - isolated contacts of the sabotage micro switch – shorted when the detector installed.

1. 1. GNW12 base for fire alarm systems - data sheet
   23-gnw12-kk-090730-en.pdf