A clapping type electromagnetic tripping system comprises an iron core with a U-shaped structure, an armature, a heating element, a bimetallic element and a connecting plate; a bracket extends into a U-shaped groove of the iron core and is fixedly connected with the iron core, and a wire connecting the heating element and the connecting plate surrounds the iron core and the bracket; the bracket twined round by the wire is fixedly connected with the middle part of the heating element, the bottom end of the heating element and the bottom end of the bimetallic element are fixedly connected with a supporting member together, and the armature is hung on the bracket surrounded by the wire; and the armature and the iron core twined round by the wire are arranged oppositely to form a magnetic loop, and one end of the armature is attracted by the iron core so as to swing when short-circuit current is generated. The clapping type electromagnetic tripping system disclosed by the present invention-creation is simple and reasonable in structure and can enable the armature to be attracted reliably.

A trip device for a circuit breaker comprises a first terminal; a second terminal; and a bimetal in which a slot with one side opened is formed at one end of the bimetal, the one end is divided into a first end portion and a second end portion, the first end portion is connected to the first terminal, and the second end portion is connected to the second terminal, wherein the bimetal generates heat with a current which flows between the first end portion and the second end portion, and a heating amount of the bimetal is changed based on a length of the slot. Accordingly, a desired rated current can be set, the bimetal can be prevented from being damaged by a fault current, and the fault current can be effectively detected by obtaining a sufficient amount of heat and a bending amount of the bimetal.

Embodiments provide a circuit breaker having a relatively low instantaneous current level at tripping. The circuit breaker includes a tripping mechanism coupled to a moveable electrical contact, the tripping mechanism including a tripping unit having a magnet, a bimetal member extending alongside of the magnet and having a moveable end, and an armature including an engagement portion being moveable as a result of motion the moveable end to trip the circuit breaker upon exceeding an instantaneous current level, and either the armature or the bimetal member includes a non-magnetic separating piece preventing a magnetic short circuit. System and method aspects are provided, as are other aspects.

Embodiments provide tripping unit of a circuit breaker. The tripping unit includes a magnet, a bimetal member extending alongside of the magnet, and an armature pivotable on the magnet, wherein the armature having an engagement portion engageable with the bimetal member at a moveable end of the bimetal member. Circuit breakers including triggering mechanisms and tripping units are also disclosed, as are low-profile, electronic circuit breakers including a maximum transverse width (Wt) limited to occupy only a single standard breaker panelboard location. System and methods are provided, as are other aspects.

The present disclosure relates to a manual motor starter and, more specifically, to a trip device for a manual motor starter. A trip device for a manual motor starter according to an embodiment of the present disclosure comprises: a trip unit body forming the base of a trip unit; a fixed contact coupled to the lower portion of the trip unit body; a heater assembly inserted and coupled to the trip unit body and detecting the heat variation; a coil coupled to the upper portion of the trip unit body; a core unit inserted into the coil; a terminal rod coupled to the core unit and the trip unit body, and having one end portion forming a terminal unit; and an instant trip lever which is rotatably coupled to the trip unit body and is operated by the core unit, wherein a coil attachment portion in which the coil is inserted and installed protrudes from the trip unit body.