The SMZ 10 and SMZ 30 central fault-alarm units are supplied in a wall housing and can be expanded with quintuple alarm lines for up to 30 alarms. Later extension to up to 50 alarms uses the SEG 20 fault alarm extension device.

Realised with the Type SMZ 50 for up to 50 alarms. The plug-in modules are identical to the SMZ 10/30 central units. The SMZ 50 can be inserted into absolutely any 19" housing. The soldering and plugging connections are to be found on the back of the base plate. When over 50 alarms are necessary any extensions can be performed using an EBT 70 extension group carrier. For each EBT 70 an extension involving a further 70 alarms is possible using the same modules. A correspondingly large mains power supply and accumulators are then used.

Parallel boards
Available for 10, 20 or 40 alarms in wall housings. They can be used for both 12 V and 24 V operating voltage. The common reference potential can be + or – Ub. A buzzer and a key for switch-off and light testing are also available.
Potential-free 'closing' and 'opening' contacts can be connected to the central fault-alarm units. The terminating resistance is 12 K-Ohms. An alarm is issued in the event of a short-circuit or interruption of the alarm line. If a fault-alarm line is activated the relevant LED display flashes and the built-in buzzer sounds. Activation of the reset key on the main module stops the buzzer and switches the flashing over to a constant light.
The optical display stops as soon as the fault criterion no longer obtains. Every quintuple fault-alarm module has an alarm relay. The relay switches in the event of an alarm and returns to its original position if the reset key is activated. Connection of a parallel display (LED) for each alarm line is possible. If required, central fault-alarm units with built-in plain-text printers can also be supplied.