With the arrival of the thunderstorm season, it brings great security risks to the monitoring equipment, which may cause the loss of the monitoring picture or the instability of the picture, or lead to the breakdown of entire system.
1. The damage of lightning to video surveillance system.
Lightning that damages the stability of video surveillance system mainly includes direct lightning, inductive lightning (including electrostatic induction and electromagnetic induction). The direct lightning is rapid discharges between charged clouds (thunder clouds) and buildings, other objects, the earth or lightning protection devices. Inductive lightning is also known as the lightning induction or over voltage induction, including electrostatic induction lightning and electromagnetic induction lightning.
a) Damage to front-end device
Most of the cameras of the monitoring system are installed in outdoor, where the equipment or cables are in greater risk of getting damaged by direct lightning . In addition, it is also very sensitive to electromagnetic interference such as over voltage of lightning & power system operation, and electrostatic discharge etc., which is easy to cause equipment damaged, and may cause the breakdown of whole monitoring system if serious.
b) Damage to transmission line
According to research, induction lightning is easy to damage transmission lines mostly. It can invade the system by power cables, video lines, network lines and antennas, etc to get the device damaged.
c) Damaged to back-end device
When the power line, signal line of the monitoring system or other metal cables which entering the control room are struck by lightning or induced by lightning, and the back-end devices would be damaged by e a high potential difference caused by lightning waves through the cables. Most of all, if there isn’t thunder protection on the switches in the monitor room, it is easy to get damage.
2. Hardware failure of switch caused by lightning
It shows that lightning is the major factor that causes hardware failure and affects the stability of switch. Power failure, port failure and cable failure of the switch caused by lightning occur frequently.
- Power failure: The external power supply of the switch is unstable, the power cable is aging or lightning strikes and other reasons are easy to lead to power failure. What’s more, damage to other parts of the machine due to power supply is often caused.
- Port failure: If a segment of the twisted pair connected to the switch port is exposed to the outdoor. And in case, the cable is struck by lightning, it will result in the connected switch port being damaged or the unexpected damage to other equipment.
- Cable failure: Even the cable failure do not belong to the switch itself, in practical use, it often leads to the switch system or port not working properly. The equipment may not be able to be used because of cable damage caused by lightning strikes.
Therefore, the design of switch thunder protection is very important to prevent such damages.
3. Anti-surge engineering project exclusive switch
In order to prevent the switch from being damaged by lightning, UTEPO has launched the P Series 5/8 ports anti-surge switches with 6KV surge immunity, which is special designed for security monitoring projects.
The protective circuit of this series adopts TSS discharge tube, which can reach the lightning protection level of 6KV, which can prevent the switch damage caused by lightning strike or the loss of monitoring picture. The product adopts high performance P0640SC protection device and can pass the common mode lightning test standard of 6kv-8/20us or 1.2/50us waveform.