| 摘要 |
<p>PURPOSE:To provide a CT secondary circuit opening safety device which shortcircuits the secondary circuit in a short time when an abnormal voltage is generated, by installing two electrodes made of a low melting point metal opposingly with a fine gap reserved in-between so that discharge takes place with a specified voltage. CONSTITUTION:With a fine gap 4 in-between, two electrodes 3, 3 are installed opposingly in a cylindrical vessel 2 made of an electrically insulative material, and leads are connected with them so that a CT secondary circuit opening safety device 1 is formed. The dimensions of the micro-gap 4 should be such that discharge takes place with a specified voltage. At least one of the electrodes 3, 3 is made of a metal or alloy having a low melting point, for example, solder. The safety device is connected with the secondary circuitry of a current transformer in such a way as parallel with the load. When the secondary circuit is opened and a failed voltage is generated, discharge is generated in the micro-gap 4 with the specified operating voltage, and the electrodes 3, 3 are melted and shortcircuited. Thereby the secondary circuitry can be maintained in the shortcircuited condition certainly and in a short time using a safety device of simple structure.</p> |
