Patent ID: 11953553
Assignee: LS ELECTRIC CO., LTD.
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G  H

Claim 0:
1. A contact monitoring device for a vacuum circuit breaker, wherein the vacuum circuit breaker includes a push rod assembly coupled to a movable electrode of a vacuum interrupter to raise or lower the movable electrode,
wherein the contact monitoring device comprises:
a discriminative sticker attached to an outer circumferential surface of the push rod assembly, extending along a moving direction of the push rod assembly, and composed of a plurality of areas whose reflectance vary step by step;
a photosensor module including:
a light-emitter facing toward the discriminative sticker and emitting light toward the discriminative sticker;
a light-receiver facing toward the discriminative sticker and receiving light reflected from the discriminative sticker; and
a circuit coupled to the light-emitter and the light-receiver, wherein the circuit processes a signal from the light-receiver and obtains an amount of current according to intensity of the reflected light, based on the processing result; and

a data processing device communicating with the photosensor module, wherein the data processing device is configured to
determine a movement amount of the push rod assembly from a withdrawn state to an inserted state of the movable electrode based on the amount of the current obtained by the photosensor module and to calculate a contact wear amount based on the movement amount; and
in response to a state of the movable electrode remaining in the inserted state or the withdrawn state for a predefined period of time, applying a correction to the contact wear amount determined based on the movement amount, the correction based on:
an open position of the push rod assembly of the vacuum circuit breaker based on the voltage output value output from the photosensor module, when the vacuum circuit breaker has remained in the withdrawn state for the predefined period of time; or
a closed position of the push rod assembly of the vacuum circuit breaker based on the voltage output value output from the photosensor module, when the vacuum circuit breaker has remained in the inserted state for the predefined period of time.