| 摘要 |
PURPOSE: To enhance overcurrent protection effect by regulating the gradient of long delay characteristics of an overcurrent protector thereby enhancing coordination with other overcurrent protection units included in a distribution system and selectivity thereof. CONSTITUTION: A set value is programmed in an overcurrent trip unit by depressing the ACTIVATEPROGRAMMODE of a membrane switch D88 on a front panel F20. Set values of various phases, ground overcurrent and instantaneous trip function including the gradient of long delay part of an overcurrent protective curve are selected by depressing SELECT of the membrane switch D88. In this regard, various LEDs 60 related to long delay, short delay pickup, instantaneous delay and slope are lighted sequentially. When an LED close to required setting of characteristics is lighted, LOWER, RAISE of the membrane switch D88 are depressed until an expected set value appears at a display section D86. When a required set value is reached SAVESETPOINTS is depressed and a selected set value is stored. |
