When communicating with customers about pre-sales and after-sales issues, in addition to consulting on the installation methods of metal oxide arresters and high-voltage arresters, most of the inquiries are about the requirements for wiring and cables. Many friends come into contact with this lightning protection industry because they are not from this industry, but are only in the safety and weak current industry related to this industry, or even other industries that have nothing to do with this industry. Therefore, there was also no idea of the cable requirements to connect the arresters due to fear of problems. Now the arrester manufacturer will introduce an overview of the cable requirements of high-voltage arresters, hoping to help you and resolve your temporary concerns when installing arresters and selecting cables.
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 better the durability. The smaller the safety accident, the higher the cost, the inconvenient installation, and the inevitable increase in installation labor costs. Therefore, as long as the cable can bear it, a smart person will definitely not choose the smallest, but the smallest.
So, what is the most suitable cable for high voltage surge arrester? The lightning arrester manufacturer will introduce it to you.
This cannot be generalized, not all are created equal. Depending on the current capacity of the arrester, the installation level, whether it is a phase line or a neutral line, a ground wire, etc., and whether it is a power arrester or a signal arrester, the cable also has a lot to do with it. Now let me introduce the relevant wiring requirements according to different situations.
As we all know, according to national standards, high-voltage arresters are generally divided into primary, secondary and tertiary levels. The minimum current capacity of the first level must be greater than or equal to 120ka, the minimum current capacity of the second level must be greater than or equal to 80kA, and the minimum current capacity of the third level must be greater than or equal to 40ka. We then divided the differences based on national standards. The phase and neutral cables on the first floor must be greater than or equal to 16 square meters, the ground wire must be greater than or equal to 25 square meters, the phase and neutral cables on the second floor must be greater than or equal to 10 square meters, the ground wire must be greater than or equal to 16 square meters, the phase and neutral lines on the third floor 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.
However, it will not be applied mechanically. For example, in the case of less lightning, a 100kA arrester can also be used as a first-level arrester. Its cable selection can be thicker or thinner, 16 or 10 can be selected as the neutral wire of the live line, 16 and 25 can be selected as the ground wire, and then 60kA can also be used as the second and third levels, there are many selection methods. Of course, if the economy can afford it, the smallest option is to go with something rougher.
Now let's look at signal high voltage arresters. Signal arresters include all weak current types, such as network, video, control, etc. Since the voltage of the signal arrester in contact with the device is relatively small, the wiring requirements are much looser than the power arrester, so the wiring of the signal type is also similar. Since it is connected in series at the front end of the device, the connecting wire matches the previously connected device. Only the ground wire has significant requirements. Generally speaking, we require it to be greater than or equal to 6 square meters.
There are two situations in theory, but in practice, we can choose different arrester cables according to local conditions and different minefields and environments. However, we must pay attention to one very important thing, that is, the ground wire is slightly thicker than the phase wire and neutral wire, because the ground wire is after all the core of the entire arrester and where all lightning flows. If it is not rough and does not age quickly, safety accidents may easily occur.
In addition to detailing cables, options for cable appearance are also covered. In fact, like all other electrical equipment in the distribution room, the cable colors of our metal oxide arresters are usually red for the phase wire, light blue for the neutral wire, and yellow and green for the ground wire. Electrical conduits are generally required to be yellow for strong current and light yellow for weak current, and must have flame retardant insulation effect.
