Case studies(Introduction examples)

Lightning protection for automatic fire alarm systems

Automatic fire alarms with crossings between buildings and wiring leading to outdoor equipment are susceptible to lightning surges.

Automatic fire alarm receivers installed in disaster prevention centers and security offices receive signals from detectors and transmitters connected to each floor and building, display them, and send out alarms to the building, but it is possible that a failure due to lightning damage may prevent the alarm from being sent out. Also, if multiple buildings are being monitored, they are more susceptible to lightning surges, so countermeasures are necessary. Especially in the case of important facilities and cultural properties, failure or malfunction of automatic fire alarms due to lightning surges is not acceptable.

Dangers if no measures are taken
  • Automatic fire alarm receivers, detectors and transmitters are damaged by lightning surge.
  • Automatic fire alarm malfunctions or fails due to lightning surge.

Lightning protection points for automatic fire alarm systems

Countermeasure points
If the wiring length is long or there are signal lines running between buildings, install a SPD for signal lines (SPN-Z24J, SPN-Z48J) near the receiver. Install an SPD for the power supply on the power supply side of the receiver. To increase the protection effect, install each SPD (SPD for signal lines and SPD for power supply) as close as possible to the automatic fire alarm system. This is because the SPD wiring should be connected at the shortest distance possible, so that the lightning protection effect can be achieved with as little influence as possible from the length of the connecting lead wires.

In addition, the risk of failure due to lightning surges can be reduced by attaching SPDs for signal lines to floor terminal panels, etc., for the terminal detectors.
In addition, automatic fire alarm systems have R-type, P-type, and other types of receivers, and SPDs can be installed in any of these receivers.

Installation example

Lightning protection products for automatic fire alarm systems