A monitoring system includes a frame, a fixed contact, a moveable contact, a drive mechanism, and a linkage mechanism, wherein the fixed contact is fixed in position with respect to the frame, and wherein the linkage mechanism is coupled to the drive and the moveable contact, and wherein activation of the drive is configured to move the linkage mechanism such that the moveable contact is moved towards or away from the fixed contact, and wherein the monitoring system comprises a sensor system having a position sensor and a processor, the position sensor configured to be positioned with respect to the frame and the linkage mechanism such that lateral movement of a part of the linkage mechanism generates at least one displacement signal; and the processor configured to convert the at least one displacement signal to a displacement movement of the moveable contact toward or away from the fixed contact.

A circuit breaker monitoring system and method includes a vibration sensor, a processing unit, and an output unit. The vibration sensor is configured to be mounted to a circuit breaker and to acquire a temporal vibration signal over at least a temporal portion of a closing operation of the circuit breaker. The closing operation comprises: initiation of the closing operation; latch release; movement of a moveable contact towards a fixed contact; contact touch of the moveable contact with the fixed contact; stop of movement of the moveable contact. The sensor provides the temporal vibration signal to the processing unit, which determines a plurality of physical switch events and corresponding plurality of time points of the plurality of physical switch events over the closing operation of the circuit breaker.

A circuit breaker monitoring system and method includes a vibration sensor, a processing unit, and an output unit. The vibration sensor is configured to be mounted to a circuit breaker and to acquire a temporal vibration signal over at least a temporal portion of a closing operation of the circuit breaker. The closing operation comprises: initiation of the closing operation; latch release; movement of a moveable contact towards a fixed contact; contact touch of the moveable contact with the fixed contact; stop of movement of the moveable contact. The sensor provides the temporal vibration signal to the processing unit, which determines a plurality of physical switch events and corresponding plurality of time points of the plurality of physical switch events over the closing operation of the circuit breaker.

A system and method for monitoring a circuit breaker monitoring system includes a vibration sensor, a processing unit, and an output unit. The vibration sensor is mounted to a circuit breaker acquires a temporal vibration signal over at least a temporal portion of a closing operation of the circuit breaker, wherein the closing operation comprises: initiation of the closing operation, latch release, movement of a moveable contact towards a fixed contact, contact touch of the moveable contact with the fixed contact, and stop of movement of the moveable contact. The vibration sensor provides the temporal vibration signal to the processing unit, which determines a plurality of features of the closing operation and an indication of operational functionality of the circuit breaker.

A system and method for monitoring a circuit breaker monitoring system includes a vibration sensor, a processing unit, and an output unit. The vibration sensor is mounted to a circuit breaker acquires a temporal vibration signal over at least a temporal portion of a closing operation of the circuit breaker, wherein the closing operation comprises: initiation of the closing operation, latch release, movement of a moveable contact towards a fixed contact, contact touch of the moveable contact with the fixed contact, and stop of movement of the moveable contact. The vibration sensor provides the temporal vibration signal to the processing unit, which determines a plurality of features of the closing operation and an indication of operational functionality of the circuit breaker.

An electromagnetic relay diagnostic device includes: an operation detection unit including a first light-emitting unit emitting light when a current flows through a wiring line connected to a coil of an electromagnetic relay; an operation detection unit including a second light-emitting unit emitting light when a current stops flowing through the wiring line; an operation detection unit including a third light-emitting unit emitting light when detecting a change in conductive state of a wiring line connected to a contact of the electromagnetic relay; an operation detection unit including a fourth light-emitting unit emitting light when detecting that the change in conductive state of the wiring line has disappeared; an imaging unit capturing a moving image of the operation detection units; and a diagnostic unit calculating a contact-on operation time and a contact-off operation time using the moving image, and diagnosing whether an abnormality has occurred in the electromagnetic relay.

The present invention is provided with: a first contact in a first relay connected to a circuit to be grounded; a resistor which is connected between the first contact and the earth, and which suppresses the flow of electric current to the first contact when the first contact is closed; a second contact in a second relay connected in parallel to the resistor; and an interlocking control means which inhibits opening of the first contact in a closed state when the second contact is opened, and which inhibits closing of the first contact in an open state when the second contact is closed.

A diagnostic test instrument for testing power system equipment may include a chassis having a number of bays capable of receiving test circuitry modules, which may be field inserted by a user desiring to perform a particular test. The instrument may include controller circuitry that may sense in each of the bays whether a respective test circuitry module is inserted therein, and then interrogate respective test circuitry modules in each respective bay to identify a type of the respective test circuitry module. Available testing capabilities may be identified according to the type of each of the respective test circuitry modules identified in respective bays. The controller circuitry may output configuration instructions to test circuitry modules, and respective test ports included in each of the respective test circuitry modules may be selectively illuminated as a configuration instruction to visually identify an assigned functionality of the respective test ports.

A state of a tripping solenoid in a circuit breaker is determined by a primary coil and a secondary coil wound around a hollow body of a solenoid. The secondary coil is positioned within magnetic coupling distance from the primary coil and is configured to produce a sensing voltage based on the primary coil voltage. A ferromagnetic plunger positioned in the hollow body, is configured to slide axially to a tripped position to trip the circuit breaker when a trip voltage is applied to the primary coil. A plunger position detecting circuit connected to the secondary coil, is configured to detect the position of the plunger in the hollow body of the solenoid based on the sensing voltage. A reduction or absence of the sensing voltage indicates a faulty or broken connection in the primary coil.

A power supply on-off detection circuit includes: a signal acquisition circuit, a signal conversion circuit, and a signal processing circuit. The signal acquisition circuit is coupled to a power supply through a switch, and is configured to collect an alternating current signal output by the power supply, and to output the alternating current signal to the signal conversion circuit. The signal conversion circuit is configured to convert the alternating current signal into a voltage signal, and to output the voltage signal to the signal processing circuit. The signal processing circuit is coupled to the signal conversion circuit, and is configured to convert the voltage signal into a level signal. The level signal is used to determine whether the power supply is on or off by determining whether the switch is switched on or off.