Current parameters of high-voltage switches
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Current parameters of the high-voltage switch: Rated current – 2500A; Rated impulse current (dynamic stability, peak value) – 100KA; Rated short-circuit making current (peak value) – 100KA; Rated short-circuit withstanding current (thermal stability) – 40KA, 3s. QUESTIONS: Q1: Is the rated short-circuit making current (peak value) equal to the rated impulse current (dynamic stability, peak value)? Q2: Is the rated short-circuit withstanding current (thermal stability) of 40KA, 3s equal to the rated short-circuit withstanding current (thermal stability) of 4KA, 30s?
1. Online information: Since the inrush current during a short circuit is basically 2.5 times the steady-state short-circuit current, when the thermal stability current meets the requirements of the short-circuit current at the installation location, the dynamic stability current is generally not a problem. The rated dynamic stability current primarily assesses the circuit’s ability to withstand electromagnetic forces. Rated short-circuit making current (peak value): The peak value of the first major half-wave of the current in one pole of the circuit breaker during the transient period that follows the occurrence of current during a making operation. This value also serves as an indicator of the circuit breaker’s ability to withstand short-circuit impulse currents, and it is equal to the rated dynamic stability current value. 2. Personally, I think that those who can handle 4KA probably cannot handle 40KA, so they are definitely not equivalent.
Q2 Rated short-circuit withstanding current (thermally stable): 40KA, 3s = Rated short-circuit withstanding current (thermally stable): 4KA, 30s