Purchase of lifting lightning Rod

Time：2021-05-19 View：

1. Reasonably select a calculation method within the range of lightning conductor protection
Commonly used calculation methods of protection range of lightning Rod (here only refers to single needle) mainly include broken line method and grounder method. The main features of "polyline method" are intuitive design, simple calculation and saving investment, but it is not suitable for buildings with a height of more than 20m; the main feature of "grounder method" is that it can calculate the protection range of ightning rod or the combination of lightning strip and grid, but the calculation is relatively complex, and the investment cost calculated by this method is relatively large.
Among these two calculation methods, "Broken line method" is a relatively mature method, which is also called "regulation method" in power system ", that is, the protection range of a single ightning Rod is a folded cone with a ightning Rod axis. The protection scope of a single ightning rod is stipulated in DL/T620-997 "overvoltage protection and insulation coordination of AC electrical equipment" standard; "grounder law" is the International Electrotechnical Commission (IEC) one of the recommended methods for calculating the protection range of the lightning receiver. In the GB50057-1994Z of China's building lightning protection code, the "grounder method" is also mandatory as a method to calculate the scope of lightning conductor protection. The grounder method uses a sphere with a radius of hR to roll along the part that needs to prevent Thunder attack. When the sphere only touches the lightning receiver (including the metal used as the Lightning receiver) or only touch the lightning receiver and the ground (including metal objects that come into contact with the Earth and can withstand lightning strikes) without touching the parts that need to be protected, this part will be protected by the lightning receiver. In recent years, the "grounder law" stipulated in the national standard has also begun to be recognized by the industry, but in practical application, the "grounder law" has also encountered some problems, especially when calculating the sky lightning conductor protection range. Generally speaking, these two algorithms have their own characteristics, and generally high-rise buildings use "grounder method" more ".

2. Can it be safe to discharge ightning rod in advance after using it?
In fact, no lightning protection equipment is foolproof. In the protection range, there is not no lightning strike, but the Lightning Strike Energy is relatively small. From the economic point of view, it will be a waste to achieve safety. Therefore, "code for design of lightning protection of buildings" and other design codes and standards have all "reduced" Lightning strikes as requirements. Therefore, the lightning protection safety of lightning protection devices designed according to national and international standards is not 100%. In addition to direct thunder, high-rise buildings may also be affected by side lightning and induction lightning.
There are two main advantages of early discharge ightning Rod. One is that it can "discharge in advance" and has better Lightning-induced performance than ordinary ightning rod. The second is to convert its early discharge time into the early discharge distance, which is equivalent to an increase of ightning rod in height, thus increasing the protection radius. However, there is still no way to protect side lightning and induction lightning.

 

3. It is very important to ensure ightning Rod flow discharge capability
All kinds of Lightning Protection specifications require ightning rod to have independent grounding, which can ensure that lightning current can quickly leak into the earth. When purchasing, you must never listen to the suggestions of some irregular manufacturers, and connect ightning rod to the grounding system of the building itself to save costs.

 

4. It is very important to choose regular lightning protection manufacturers.
Ightning rod is actually lightning rod, so the lightning protection project needs rigorous scientific calculation, and a little carelessness may lead Thunder into the room instead ". Therefore, when selecting ightning Rod suppliers, you need to check whether they have the professional design qualification of Lightning Protection Engineering and the professional construction qualification of Lightning Protection Engineering. The domestic ightning Rod market is mixed, and some distributors acting for foreign brands have publicized that their products conform to advanced foreign standards, among which true and false are hard to distinguish. It is recommended that the products be inspected according to the national standard and IEC standards when purchasing.