Choix du dispositif de protection contre les surtensions
La sélection de Dispositif de protection contre les surtensions s'effectue de la manière suivante.
Step 1: Select Uc, UT, In, Imax of Dispositif de protection contre les surtensions. The maximum continuous operating voltage of the Dispositif de protection contre les surtensions is much larger than that of the power system, and the transient overvoltage of the Dispositif de protection contre les surtensions is much larger than that of the grid.
Step 2: Determine the protection distance, that is, determine the location of the Dispositif de protection contre les surtensions.
Step 3: Anticipate the life and failure modes of the Dispositif de protection contre les surtensions.
Step 4: Interrelationship between Dispositif de protection contre les surtensions and other electrical appliances. Under normal circumstances, Ic will not cause any personal safety hazards and damage other equipment; when a fault occurs, Dispositif de protection contre les surtensions will not affect other electrical appliances, such as RCD or circuit breaker. The surge coordination between the Dispositif de protection contre les surtensions and the overcurrent protector, when it is less than Imax, the overcurrent protector does not operate; when it is greater than or equal to Imax, the overcurrent protector is allowed to operate, but it cannot cause any damage.
Step 5: La sélection de voltage protection level Uₚ doit tenir compte de la capacité de tenue aux surtensions Uw de l’équipement protégé.
Step 6: When two Dispositif de protection contre les surtensionss are used on the same conductor, the cooperation between the selected Dispositif de protection contre les surtensions and other Dispositif de protection contre les surtensionss should be considered.
L'utilisation de Dispositif de protection contre les surtensions is different in different grounding methods. On the one hand, because of the different characteristics of the protection under different grounding methods, the installation location is also different; on the other hand, the Dispositif de protection contre les surtensions cooperates with the leakage protection device, in order to avoid the current when the Dispositif de protection contre les surtensions operates may cause the leakage protection of the upper level at the same time The device malfunctions, so the Dispositif de protection contre les surtensions needs to be installed with corresponding protection devices, such as circuit breakers or fuses, on its upper level during installation.
