TRIP MECHANISM AND ELECTRICAL SWITCHING APPARATUS INCLUDING A TRIP MEMBER PUSHED BY PRESSURE ARISING FROM AN ARC IN AN ARC CHAMBER

摘要

An electrical switching apparatus (2;50) includes separable contacts (10), an operating mechanism (16) structured to open and close the separable contacts, and a trip mechanism (14) cooperating with the operating mechanism to trip open the separable contacts. The trip mechanism includes a trip latch (4), and an arc chamber (18) operatively associated with the separable contacts. The arc chamber includes a plurality of arc plates (20) and a barrier (22) disposed between the arc plates and the trip latch. The barrier has an opening (12;58) therein. A trip member (8) is disposed in or about the opening of the barrier of the arc chamber. During interruption of current flowing through the separable contacts, pressure arising from an arc (11) in the arc chamber pushes the trip member away from the barrier of the arc chamber to engage the trip latch and cause the trip mechanism to trip open the separable contacts.