摘要 |
<p>The indicating device (3) is used for signalling a faulty condition of an electrical apparatus, in particular of a surge arrester (1). It contains a sensor (resistor 10) which is located in an insulating material housing (6) and is intended for detecting a fault current flowing through the apparatus, as well as a two-piece metal housing (4) surrounding the insulating material housing (6). The sensor (10) and the insulating material housing (6) are part of a switching element (5). This switching element (5) causes the insulating material housing (6) to spring apart, by the formation of compressed gas, when the fault current occurs and displaces the two parts of the metal housing (4), making the indicating element (16) visible and forming a DC connection which carries the fault current.</p> |