Importance And Precautions For Selecting Primary Surge Protector
In the power system, the primary surge protector (SPD) plays a key role in preventing surge damage. How to correctly select the primary surge protector is crucial to the safety of the system. This article will introduce how to select a suitable primary surge protective device and provide a selection guide for the selection of relevant primary surge protectors.
1. Installation location and requirements of primary surge protectors
According to the provisions of Article 4.3.8 of the national standard GB 50057-2010, when the electrical grounding device is shared or connected with the lightning protection grounding device, a Class I test surge protector should be installed at the main distribution box and distribution cabinet where the low-voltage power line is introduced. Ensure that the primary surge protector is installed in the correct location to provide the best protection effect.
2. Choose the appropriate type of primary surge protector
Selection of primary surge protectors: Types include voltage limiting type, switch type and composite type. When selecting, it is necessary to consider the characteristics and applicable scenarios of different types. The voltage-limiting SPD may have leakage current and short life problems, the switch-type SPD may cause the front-stage switch to trip, and the composite SPD combines the advantages of both, no continuous current, no leakage current, long life, and will not cause the main circuit switch to trip.
3. Selection of appropriate primary surge protection device flow rate
The flow rate of the primary surge protector is a key consideration when selecting. Common flow rates include 12.5KA, 15KA, 25KA, 50KA, 100KA and other options. Choose the appropriate flow rate according to specific needs and budget. The larger the flow rate, the higher the price, but it also provides higher protection capabilities. The 25KA primary surge protector is often selected in the project, and the price is also moderate, which can be used in buildings of any lightning protection level.
4. Consider the automatic energy coordination function
When setting up multiple surge protectors on a line, energy coordination is an important factor. According to GB50343-2012, Section 5.4.3.10, when the surge protector has the function of automatic energy coordination, it can eliminate the limitation of installation distance, simplify the installation process, and improve the safety of the system.
Correct selection of primary surge protector is a key step to ensure the safe operation of the power system. By selecting the appropriate type, installation location and flow rate, and considering the automatic energy coordination function, reliable protection measures can be provided.
