Back to results
US 5,182,532 AGranted
Thermal-magnetic trip unit
AssigneeGeneral Electric Company
InventorKeith W. Klein
Life of this patent
Estimating the term…
Abstract
A molded case thermal-magnetic circuit breaker having improved low current magnetic trip response interfaces an intermediate armature between the circuit breaker latching element and the magnet assembly within the circuit breaker thermal-magnetic trip system. The intermediate armature optimizes the magnetic trip forces applied to both the intermediate armature and the latching element to enhance low current magnetic trip response.
Claims23
A thermal-magnetic trip unit for molded case circuit breakers comprising:
- a thermally-responsive electrically-conductive element arranged within an insulative case for connection with a circuit breaker line or load strap;
- a stationary magnetically-responsive element at least partially surrounding said electrically-conductive element arranged for providing a magnet force in proportion to current transfer through said electrically conductive element;
- a movable magnetically-responsive latching element arranged a predetermined separation distance from said stationary magnetically-responsive element to define a first magnet gap, said movable latching element retaining a circuit breaker releasable element under quiescent current through said electrically-conductive element and releasing a circuit breaker releasable element under a first overload current through said electrically-conductive element;
- and
- a movable intermediate armature between said stationary magnetically-responsive element and said movable latching element, said intermediate armature thereby moving toward said stationary magnetically-responsive element reducing said magnetic gap and causing said latching element to release said circuit breaker releasable element under a second overload current lower than said first overload current.
2 more elements
A low magnetic trip responsive circuit breaker comprising:
- a circuit breaker operating mechanism within a circuit breaker enclosure arranged for automatic interruptino of circuit current upon occurrence of an overcurrent condition of predetermined magnitude and duration;
- a releasable element attached to said operating mechanism restraining said operating mechanism under quiescent current and releasing said operating mechanism upon occurrence of said overcurrent condition;
- a thermally-responsive electrically-conductive element arranged for connection with a circuit breaker line or load strap;
- a stationary magnetically-responsive element at least partially surrounding said electrically-conductive element arranged for providing a magnet force in proportion to current transfer through said electrically conductive element;
- a movable latching element arranged a predetermined separation distance from said magnetically-responsive element to define a first magnet gap, said latching element retaining said releasable element under quiescent current through said electrically-conductive element and releasing said releasable element under overload current through said electrically-conductive element;
- and
- a movable intermediate armature between said magnetically-responsive elemetn and said latching element, said intermediate armature thereby providing a second magnetic gap upon occurrence of said overload current, said second magnetic gap being lower than said first magnetic gap.
4 more elements
A thermal magnetic trip unit for circuit breakers comprising:
- a thermally-responsive electrically-conductive element arranged for connection with a circuit breaker line or load strap;
- a magnetically-responsive element at least partially surrounding said electrically-conductive element arranged for providing a magnet force in proportion to current transfer through said electrically conductive element;
- a latching element movably arranged a predetermined separation distance from said magnetically-responsive element to define a magnet gap, said latching element arranged for retaining a circuit breaker releasable element under quiescent current through said electrically-conductive element and releasing a circuit breaker releasable element under overload current through said electrically-conductive element;
- and
- a force amplifier armature movably arranged on said latching element for contacting a circuit breaker releasable element and providing a displacement force against said circuit breaker releasable element in propotion to said current transfer through said electrically-conductive element.
2 more elements
A low magnetic trip responsive circuit breaker omprising
- a circuit breaker operating mechanism within a circuit breaker enclosure arranged for automatic interruption of circuit current upon occurrence of an overcurrent condition of predetermined magnitude and duration;
- a releasable element attached to said operating mechanism restraining said operating mechanism under quiescent current and releasing said operating mechanism upon occurrence of said overcurrent condition;
- a thermal-magnetic trip unit within said enclosure comprising a magnetically-responsive element at least partially surrounding said electrically-conductive element arranged for providing a magnet force in proportion to current transfer through said electrically conductive element;
- a latching element pivotally arranged a predetermined separation distance from said magnetically-responsive element to define a magnet gap, said latching element arranged for retaining a circuit breaker operating cradle under quiescent current through said electrically-conductive element and releasing a circuit breaker operating cradle under overload current through said electrically-conductive element;
- and
- a force amplifier armature mounted on said latching element and privotally arranged for contacting a circuit breaker operating cradle and providing a displacement force against said circuit breaker operating cradle in proportion to said current transfer through said electrically-conductive element.
3 more elements
Dependencies are inferred from the claim text.