When communicating with customers and friends about pre-sales and after-sales issues, in addition to consulting on the installation method of lightning protection devices, more inquiries are about the requirements for wiring cables. Many friends come into contact with the lightning protection industry because they are not in this industry. They are only in the safety and weak current industry related to this industry, or even other related industries. Therefore, I have no idea about the cable requirements for connecting lightning protection devices, and I am afraid that problems may occur. Now the editor will introduce the cable requirements of lightning protection devices. The lightning arrester manufacturers hope to help you choose cables when installing lightning protection devices and solve your temporary concerns.
In fact, it can be said that when conditions permit, for the sake of safety, the thicker the wires and cables, the better the conductivity and the longer the durability, so the better, the smaller the safety accidents, but the higher the cost, the installation is also very inconvenient, and the installation labor cost will inevitably increase, so as long as the cable can withstand it, smart people will not choose the thickest, but the most suitable.
So what kind of cable is suitable for lightning protector?
This cannot be generalized and not all are the same. The cable also has a lot to do with the current capacity of the lightning arrester, the installation level, whether it is a phase line or a neutral line, a ground wire, etc. , and whether the power lightning protector and the signal lightning protector are different. Now let's take a look at the relevant wiring requirements I introduce based on different situations.
As we all know, power supply lightning protectors are generally divided into level one, level two and level three according to national standards. The maximum flow rate of the first level must be greater than or equal to 120KA, the second level must be greater than or equal to 80KA, and the third level must be greater than or equal to 40KA, so we will divide it according to national standards. The first-level phase neutral cable must be greater than or equal to 16 square meters, the ground wire must be greater than or equal to 25 square meters, the second-level phase neutral cable must be greater than or equal to 10 square meters, the ground wire must be greater than or equal to 16 square meters, the third-level phase neutral cable must be greater than or equal to 6 square meters, the ground wire must be greater than or equal to 10 square meters, and the connecting wire should be as short, thick, and straight as possible.
Despite this, it will not be applied mechanically. For example, when there is less lightning, a 100KA lightning arrester can also be used as a first-level lightning protector. The cable selection of a metal oxide arrester can be either thicker or thinner. The live and neutral wires can be selected as 16 or 10, and the ground wires can be selected as 16 and 25. Then 60KA can also be used as secondary and tertiary lightning arresters, with multiple options. Of course, if the economy can afford it, it is best to choose a thicker one.
Now let’s look at signal lightning arresters. Signal lightning arresters include all weak current types, such as network, video, control, etc. Since the voltage of the contact equipment is relatively small, compared with the wiring requirements of power lightning arresters, the signal wiring is similar because it is connected in series at the front end of the device, so the connecting wire matches the previous connection equipment. It only has great requirements for the grounding wire. Generally, our requirement is greater than or equal to 6 square meters.
Theoretically, these are two situations, but in actual operation, we can take measures according to local conditions and choose different lightning protection cables according to different minefields and environments. It is also possible, but we must pay attention to a very important thing, that is, the ground wire is slightly thicker than the phase neutral line, because after all, the ground wire is the core of common lightning protection work and is also the place where all lightning current leaks. It is not thick, ages quickly, and is prone to safety accidents.
In addition to introducing the thickness of the cable, let me introduce the choice of cable appearance. In fact, like all other electrical equipment in the power distribution room, the color of the cables of our lightning arresters is generally red, with a light blue neutral wire and a yellow-green ground wire. The requirements for pipelines are generally to choose yellow for strong electricity and light yellow for weak electricity. The pipeline must have flame retardant insulation effect.
