| 摘要 |
<p>The invention relates to an electric selective automatic switch, particularly a circuit breaker, having a series connection from an auxiliary trigger device (6), a normally closed first switch (8), a resistor (10), and a main trigger device (12) that is connected between a first and a second electrical connection (2, 4), a shunt current path that is connected in series to the main trigger device (12) between the first and the second electrical connections (2, 4) and that has a second switch (14), which is closed if no malfunction exists, and a normally closed third switch (16), which is connected in series to the second switch (14), and a current bridge connecting an input contact of the first switch (8) to a connection contact (18) between the second and the third switches (14, 16), wherein the main trigger device (12) is configured such that upon achieving a first threshold current the second switch (14) is opened, and upon achieving a second threshold current, which is greater than the first threshold current, additionally the third switch (16) is opened, and wherein the auxiliary trigger device (6) is configured such that the first and the third switches (8, 16) are opened after expiration of a first time duration with the second switch (14) being open, while the first switch (8) is opened after expiration of a second time duration that is shorter than the first time duration with the second and third switches (14, 16) being open.</p> |
