Patent ID: 7639107

Claim:
An overcurrent relay comprising: a calculating unit that outputs a trip signal or a reset signal to instruct supply and non-supply of power based on current information on a main circuit current supplied to a load; a power source unit that supplies power to a coil based on the trip signal or the reset signal when the trip signal or the reset signal is input; an electromagnet unit that performs a trip operation to move a movable iron core from a position of a stationary state to a position of a trip state and a reset operation to move the movable iron core from the position of the trip state to the position of the stationary state when the power is supplied from the power source to the coil based on the trip signal or the reset signal; and a contact point mechanism unit that opens a usually-closed contact point through the trip operation of the movable iron core and closes the usually-closed contact point through the automatic or manual reset operation, wherein the movable iron core arranged on sides of the coil and forms a magnetic circuit, and wherein the contact point mechanism unit includes: a movable contactor support for supporting a movable contactor composing a part of the usually-closed contact point while being maintained in the movable iron core; and a reset bar arranged in a manner that is switchable between an automatic reset setting and a manual reset setting, wherein in the automatic reset setting the reset bar does not engage with the movable contactor support in an operation range of the movable contactor support, and wherein in the manual reset setting the reset bar engages with the movable contactor support in interlock with the movable iron core to interrupt the reset operation of the movable iron core of the electromagnet unit, and when the reset operation is manually performed the reset bar engages with the movable contactor support to be moved up to a position at which the reset operation is completed, and wherein: in the stationary state in the manual reset setting a position of the reset bar in the stationary state is defined when a protrusion provided in the reset bar on which a resilient force of a spring is exerted engages with a protrusion provided in the movable contactor support, and in the trip state in the manual reset setting when the engagement of the protrusion provided in the reset bar with the protrusion provided in the movable contactor support is released, the reset bar is moved in a direction in which the resilient force of the spring is exerted, and a position of the protrusion provided in the reset bar is defined on a rotation locus of the protrusion provided in the movable contactor support to interrupt the reset operation of the movable contactor support.