| 摘要 |
The invention relates to an installation for protection against overvoltage, provided with power contacts with switching off chambers manually actuated, upon closing, by means of an exterior handling lever, and upon opening, actuated by a differential automatic switch (A). The installation comprises a device (B) for protection against overvoltage, achieved by a monitoring and controlling electronic circuit (2), having the role of monitoring the distribution network voltage and of controlling the interruption of the voltage supplying the electric energy final consumer, said device being located between two terminals (a1 and a2), each connected to one of the input terminals (n1 and p1) and the output terminals (n2 and p2), respectively of the differential automatic switch (A), so that one of the terminals (a1 and a2) of the device for protection against overvoltage (B) should be connected to one of the neutral terminal (n1 and n2) of the differential automatic switch (A), corresponding to the neutral terminal (n0) of the distribution network, and the other, to one of the line terminals (p1 and p2) of the differential automatic switch (A), so that there is performed a quasi-parallel connection with a test button (1), which the differential automatic switch (A) is provided with. The electronic circuit for monitoring and controlling (2), whichthe device for protection against overvoltage (B) is provided with, comprises an A.C.-D.C. voltage conversion block (C), performed with a monophase rectifying bridge (5) a rectified voltage being obtained at the output of the said block (C) said rectified voltage being applied through a current limiter block (D), to a reference voltage block (E), consisting of regulator diodes (7) serially connected to two resistors (8 and 9), making up a voltage divider which controls, by means of a bi-directional diode thyristor (10), the triggering of a final controlling element (F) achieved with a thyristor (11).
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