| 摘要 |
<p>PURPOSE: To carry out a stable trip operation by matching a load weight on an armature as a reactive force and the attraction characteristic of an electromagnet to effectively use the small and small-capacity electromagnet when driving a trip crossbar by the attracting operation of the electromagnet. CONSTITUTION: This electromagnetic trip device is used for tripping a circuit breaker by detecting an overcurrent in the main circuit and is so structured that an operation arm 14a formed on the armature 14 of an electromagnet unit 7 is faces a trip arm 8a of the trip crossbar 8, the operation arm presses the trip arm of the trip crossbar in the attracting operation of the electromagnet, and thus the breaker is tripped by releasing a latch receiver 9. By changing the force application point between the operation arm and the trip arm from a point P1 to a point P2 in line with the change of an air gap (g) between the armature and the electromagnet in the attracting operation of the electromagnet, the load weight applied to the armature is kept low in the first half causing small attraction, and the force application point is moved to the point P2 in the second half increasing the attraction of the electromagnet so that the trip crossbar is driven to a release position.</p> |
