Abstract:
A thermal overload relay device has a mechanism that allows the interphase pitch between connection lines to be readily changeable without using a jig or the like in the work for electrically connecting the thermal overload relay to different types of electromagnetic contactors, thereby reducing the maintenance cost. The mechanism comprises a connection line-holding structure disposed in a casing and holding the connection lines, while permitting the distances between the connection lines to be readily changeable between among at least two different interphase pitches.
Abstract:
A switching device has an input terminal and an output terminal for connection to electrical conductors, and two switching contacts which, when closed, close a current path between the input terminal and the output terminal. An overcurrent trigger device which includes a bimetallic element heated by an electric current flow is provided for disconnecting the two switching contacts. A thermal insulator is arranged in the attachment region of the bimetallic element for reducing heat transfer from the bimetallic element as well as for increasing the accuracy and the degree of reproducibility for triggering the switching device. The switching device can be implemented as a circuit breaker.
Abstract:
A thermally compensated circuit breaker has a movable contact assembly (24) which mounts a movable electrical contact (24m) for movement between open and closed contacts positions with a stationary electrical contact (26). The contacts are maintained in the closed circuits position by a latching mechanism (24b, 28g) which prevents opening of the contacts through an opening contacts force provided by a spring (24e). A current carrying trip arm (40a, 44a) deflects upon sufficient I2R heating to transfer motion to the latch to separate the latch (24b) from the latch receiving catch (28g) to trip the circuit breaker. The trip arm (40a, 44a) is part of a pivotably mounted actuator assembly (40, 44) having a movable end portion spaced from the pivot disposed adjacent a motion transfer member (28c). A calibration screw (42a) is located so that the longitudinal axis is in line with a movable end portion of the actuator assembly and the motion transfer member. In one embodiment the head of the calibration screw is captured in a slot in the free end of a calibration base (42d) attached to the trip arm so that deflection of the trip arm directly transfers motion to the motion transfer member and in another embodiment the calibration screw head is captured in a slot in the free end of the trip arm so that a bowing deflection of the trip arm causes a calibration base (46) to which it is attached at an end thereof to rotate with the calibration base directly transferring motion to the motion transfer member.
Abstract:
The circuit breaker current/time characteristic value at which the bimetal in a thermal trip assembly actuates a trip mechanism is adjusted by an adjustable coupler that includes first and second pivoted members separately rotatable about a common pivot axis. Deflection of the bimetal by an overload current causes rotation of the first pivoted member, which is coupled by a coupling member extending parallel to the common axis into the second pivoted member which rotates to actuate the trip mechanism. A positioner moves the coupling member toward and away from the common pivot axis to adjust the amount of deflection of the bimetal needed to actuate the trip mechanism.
Abstract:
A molded plastic current limiting circuit breaker includes an interrupter assembly that includes an over-molded magnet, arc stack, baffle stack, and a chamber liner in which a trip unit is described.
Abstract:
A molded plastic current limiting circuit breaker includes an interrupter assembly that includes an over-molded magnet, arc stack, baffle stack, and a chamber liner in which a trip unit is described.
Abstract:
A molded plastic current limiting circuit breaker includes an interrupter assembly that includes an over-molded magnet, arc stack, baffle stack, and a chamber liner in which a trip unit is described.
Abstract:
Apparatus for adjusting the calibration of a thermal trip unit which is to be used in conjunction with an electrical circuit breaker. A rotatable knob is provided which adjusts the trip unit to between one hundred percent of the rating of the circuit breaker and some value which is less than one hundred percent. An adjustable stop screw is provided to engage the rotatable knob when the knob is rotated to adjust the calibration of the trip unit to the desired value which is less than one hundred percent of the rating of the breaker. The adjustable stop screw thereby limits travel of the adjustable knob between only one hundred percent of the rating of the circuit breaker and the desired value which is less than one hundred percent.
Abstract:
A remotely controlled circuit control device has first and second load contact assemblies movable into circuit engagement and circuit disengagement positions relative to one another in which one load contact assembly is operatively connected to a solenoid so that alternate forward strokes of the solenoid moves the one load contact assembly between reset and tripped positions through a push-push mechanism having an indexing portion and a latching portion. An overload mechanism cooperates with the latch portion to cause the load contact assemblies to move to the circuit disengaged position upon occurrence of a fault condition. The second load contact assembly includes pivotably mounted contact members which are linked to the first load contact assembly in such a way that circuit engagement during solenoid energization is precluded. The push-push mechanism is operatively connected via a mode switch to either a reset circuit or a trip circuit and in turn to a remotely disposed indicator-control unit (ICU) through an optical coupler. Contact status and coordination between load contacts and ICU contacts are provided by a feedback circuit. An interface circuit allows operation of the circuit control device without discrimination on a power supply of either alternating or direct voltage or both. Life expectancy of the device is enhanced by several features including double break contacts with contact wiping and the provision of a floating output arm for the solenoid.
Abstract:
A remotely controlled circuit control device has first and second load contact assemblies movable into circuit engagement and circuit disengagement positions relative to one another in which one load contact assembly is operatively connected to a solenoid so that alternate forward strokes of the solenoid moves the one load contact assembly between reset and tripped positions through a push-push mechanism having an indexing portion and a latching portion. An overload mechanism cooperates with the latch portion to cause the load contact assemblies to move to the circuit disengaged position upon occurrence of a fault condition. The second load contact assembly includes pivotably mounted contact members which are linked to the first load contact assembly in such a way that circuit engagement during solenoid energization is precluded. The push-push mechanism is operatively connected via a mode switch to either a reset circuit or a trip circuit and in turn to a remotely disposed indicator-control unit (ICU) through an optical coupler. Contact status and coordination between load contacts and ICU contacts are provided by a feedback circuit. An interface circuit allows operation of the circuit control device without discrimination on a power supply of either alternating or direct voltage or both. Life expectancy of the device is enhanced by several features including double break contacts with contact wiping and the provision of a floating output arm for the solenoid.