What Are The Outdoor Lightning Protection Measures For Terminal Block?

As an electrical connector, terminal blocks are used in electrical places, or high voltage or low voltage. As long as it is an electrical place, it will be threatened by lightning. Lightning is a discharge phenomenon in the atmosphere, which is mostly formed in cumulonimbus clouds. Cumulonimbus clouds move continuously with the changes of temperature and air flow. Electricity is generated by friction in the movement, forming charged clouds. Some clouds have positive charges, others have negative charges. In addition, due to electrostatic induction, the buildings and trees under the clouds often have opposite charges. With the accumulation of electric charge, the voltage of the thunder cloud increases gradually. When the electric field between the thunder cloud with different charges and the earth protrusion is close to a certain temperature, the electric field between them exceeds 25 ~ 30KV / cm, and the intense discharge and flash will occur at the same time. As the discharge temperature is as high as 2000 ℃, the air expands rapidly when heated, and then the explosion roars, forming lightning and thunder.

Although the installation position of outdoor cable terminal block is concealed and the possibility of suffering direct lightning stroke is small, after all, some cables are connected with overhead lines or other electrical equipment, and will be invaded and affected by lightning current. Therefore, we must take more effective lightning protection measures to ensure the safe and stable operation of terminal blocks in cables.

1. Terminal selection

The construction personnel should choose the products that meet the national standards when using the terminal blocks, and control the materials. The purchasing staff should visit the grassroots more, understand the use of the purchased items in the installation process, timely collect the use opinions, select the cable accessories from the national designated manufacturers, select good wiring terminals and fittings, so as to avoid problems caused by unqualified quality standards in operation.

2. Economic and safe use of electricity

Considering the power and capacity of the user's electrical equipment, on-the-spot investigation, it is necessary to have advance in the formulation of the power consumption scheme, reasonably distribute the three-phase load, and consider both the economic efficiency and the safety of power consumption.

3. Terminal treatment

When installing the terminal, the contact surface of the terminal should be polished and coated with conductive paste to make the terminal and lead clip have a good contact, meet the requirements of the connection strength and electrical performance of the two, and reduce the chance of heating.

4. Regular inspection

The facilities that affect the safety of terminal lines should be cleared and rectified to ensure that there are no obstacles around the lines. The distribution lines led out by cables should be inspected regularly to reduce the peripheral fault factors and natural hazards of the distribution lines.

The lightning protection measures of terminal strip should be carried out from the aspects of product selection, planning, installation and treatment as well as regular inspection. In the case of economic power consumption, it is also necessary to pay attention to the safe use of electricity. At the same time, terminal manufacturers should also strictly follow the relevant national standards for the production of terminal blocks, from the source to eliminate unnecessary hazards