Abstract: An automatic trip device, a network system using it and control method thereof is related to providing the prediction of a potential electrical accident, in which measuring data including a temperature and a current from each of temperature and current sensors is received, the measuring data is stored in a data memory, the measuring data and a setting data are compared with each another and analyzed, an indicating portion display the life spans of an appliance equipment and mechanism and a power line section accommodating the interrupter, a temperature resistance coefficient based on the temperature stored is calculated, the temperature resistance coefficient is compared with one previously stored for the warning, the power line is interrupted and a warning portion is controlled to generate a warning signal if the calculated temperature resistance coefficient is higher than the warning temperature resistance one, thereby interrupting an accidental high current, rapidly, to protect persons and installments in

Abstract: An automatic temperature compensation method that automatically adjusts trip point thresholds of a motor circuit protector in response to changes in temperature. The relationship between two curves is exploited to match temperature sensor readings from a temperature sensor circuit with burden resistor percentage values derived from a burden resistor circuit. A temperature inflection point is determined from the intersection of (1) the temperature sensor curve plotting the voltage output of the temperature sensor versus temperature and (2) the burden resistance curve plotting burden resistance versus temperature. A temperature value along the temperature sensor curve is transformed into the corresponding burden resistance on the burden resistance curve. The burden resistance is expressed as a percentage variance from a burden resistance at an ambient temperature.

Abstract: An overload/open-phase tripping device for a circuit breaker includes a plurality of bimetallic elements arranged in a row; a differential shifter mechanism; and a tripping lever for transmitting a force applied by the differential shifter mechanism to a switching mechanism. The differential shifter mechanism includes a push shifter having a plurality of operation ends; a pull shifter having a plurality of operation ends; and a differential lever disposed between the push shifter and the pull shifter. The differential lever is provided with an action end for applying the force to the tripping lever upon an overload, and an action end for applying the force to the tripping lever upon an open-phase. The two action ends face the tripping lever, and the action end for the open-phase is located at a position farther from the tripping lever than the action end for the overload.

Abstract: An overload tripping device includes a temperature-compensating bimetal operating as a tripping lever and interposed between an output lever of a differential shifter mechanism linked with a main bimetal and a latch receiver of an opening-and-closing mechanism section of a circuit breaker. The temperature-compensating bimetal has an intermediate portion journaled on a bimetal holder. An operating arm made of a light molding material is attached to a tip of the temperature-compensating bimetal so as to push the latch receiver. Additionally, a balance weight may be installed on the temperature-compensating bimetal to balance inertial moments on the opposite sides of the bimetal. Thus, the circuit breaker is prevented from being inadvertently tripped due to external stimulus.

Abstract: The circuit breaker comprises a thermistor located in a cold zone, near the front face of the trip device and at least one thermistor located in a hot zone, at the bottom of the circuit breaker case, in proximity to the circuit breaker connection terminals. The temperature difference measured between the hot and cold zones is representative of the temperature rise of the system protected by the circuit breaker and is used to modify the time delay of a delayed tripping function when the circuit breaker closes. The trip device can also take into account the temperature difference existing at the time of the previous trip.

Abstract: This device comprises means for detecting, respectively, overcharges, by means of bimetallic strips and short-circuiting, by means of mobile magnetic plates effecting independently from each other the controlling of the switching off of a circuit-breaker for the protection of a circuit. The thermal safety means operate through a mechanical power amplifier comprising a cage with uprights, a rotating catch dependent on the thermal phase-detectors and a plunger transmitting the power of a spring to effect the switching off.