As far as the structured cabling system is concerned, it is a passive system. Moreover, there are some compensation devices such as PCB, resistors, and capacitors, only in the information module, distribution frame. Therefore, compared with the active system, the electrical protection of the structured cabling system is relatively simple.
Common mode interference is transmitted between the wire and the ground, which is asymmetrical interference; differential mode interference is transmitted between two wires, which is symmetrical interference; In general, small amplitude of differential mode interference and low frequency will cause small interference. The common mode interference is large and high in frequency, and radiation can also be generated through the wire, which causes greater interference. Data and telephone equipment that use structured cabling systems to transmit signals usually use differential mode, which has the advantage of being compatible with the twisted pair structure and less affected by common mode interference.
In structured cabling systems, the most common transient interferences are instantaneous interference signals such as ringing voltage, surge voltage, and lightning, which are characterized by extremely short acting time, but high voltage amplitude and large instantaneous energy, especially when meeting the lightning, the system should be specially protected.
Under ideal conditions, the equipment is properly grounded and the internal resistance of the down conductor is very low, so the structured cabling system will not be impacted. However, if the internal resistance of the down conductor is too large or the equipment grounding method is unreasonable, the system will be interfered by lightning.
In extreme cases, the equipment is grounded incorrectly and the down conductor is broken, making the structured cabling system part of the lightning protection circuit, which will cause serious equipment and personal injuries.
For structured cabling systems, according to the installation location, the system can be divided into indoor and outdoor parts. The outdoor part is usually the building interconnection subsystem, and the indoor part is the horizontal and vertical subsystems.
Since the indoor part has a complete metal bridge, building reinforced concrete structure, and grounding system ground protection, there is little possibility of lightning strikes. Therefore, the protection focus is on outdoor large-logarithmic voice cables, optical cables with reinforced steel wires and metal protective armor. And surely, it should also include telecommunications access lines.
If you have any interests of structured cabling system, welecome to contact Copperled Technology Co.,Ltd. (Tel: 0755-27896171)