Case studies(Introduction examples)

Lightning protection for central monitoring equipment

Central monitoring devices with multiple wires, such as those connected to outdoor facilities, are susceptible to lightning surges.

Central monitoring equipment that monitors and records equipment automation and malfunctions for air conditioning, production, electrical, water supply and drainage facilities is an indispensable system in this age of unmanned facilities. Monitoring controller PLCs, which monitor multiple facilities, often have multiple wires and are prone to lightning surge damage. In addition, if the central monitoring device is damaged, the real-time situation at the site becomes unclear, and there is concern that action may be delayed. Also, if multiple buildings or facilities are being monitored, they are more susceptible to lightning surges. During the replacement of the central monitoring PC or monitoring controller PLC, the situation at the site may become unclear, which may lead to a secondary disaster.

Dangers if no measures are taken
  • Damage to the central monitoring PC and monitoring controller PLC due to lightning surge.
  • Damage to on-site monitoring equipment and monitors.
  • Loss of monitoring data.

Lightning protection points for central monitoring equipment

Countermeasure points
The wiring of the monitoring controller PLC is often serial communication such as RS485 line, and the SPD for RS485 line (SRN-GV5J, SRN-GV12J, SRN-GV24J, SRN-GV38J) is used. Since the wiring between the monitoring controller PLC and the field-side equipment is expected to be long, install the SPD for RS485 lines near each of them. For the power supply circuit, install an SPD for the power supply in the vicinity of each circuit as well.

If the central monitoring PC and the monitoring controller PLC are connected by a LAN cable, install an insulated type lightning protector for LAN (model: OLA-PT1000) in the vicinity of the central monitoring PC. The insulated type lightning protector for LAN does not require grounding and does not need to be grounded on the PC side, making it easy to install. Some routers for business use may be grounded, in which case the SPD must also be grounded to make it equipotential, so connect it to a groundable SPD for lightning protector LAN (PoE+ compatible, model: OLA1000POE).

Installation example

Lightning protection products for central monitoring equipment