US 12,695,036 B2Granted

Multi-contact miniature circuit breaker with reduced arcing

AssigneeEaton Intelligent Power Limited

InventorsMichael Thomas Martin, Venkat raman Thenkarai Narayanan

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Abstract

A circuit breaker includes two sets of separable contacts in series per pole, primary contacts and secondary contacts, reducing overall let-through energy and peak pressures within the arcing chambers of the breaker during arc interruption. Opening both sets of contacts produces two arcs in series per pole, and the two series arcs increase the line to load resistance of the breaker relative to when only one set of contacts are opened. The increased line to load resistance causes the peak let-through current, Ipk, to decrease relative to what Ipk would be if only one set of contacts were to be opened. The circuit breaker also includes an internal primary vent that vents gases away from the primary contacts to another area within the circuit breaker housing, and a secondary exhaust vent that vents gases away from the secondary contacts to the exterior of the circuit breaker.

Claims12

Dependent claims

A circuit breaker, the circuit breaker comprising:

a housing;
a line side structured to electrically connect to a power source;
a load side structured to electrically connect to a load;
a first set of separable contacts, the first set of separable contacts being primary contacts electrically connected between the line side and the load side;
a second set of separable contacts, the second set of separable contacts being secondary contacts electrically connected between the line side and the load side;
a thermal magnetic arrangement configured to open the primary contacts from a closed state once current reaches a predetermined severity threshold;
a secondary actuator structured to open the secondary contacts from a closed state;
a printed circuit board, PCB, the PCB being structured to monitor electrical conditions in the circuit breaker and actuate the secondary actuator;
an internal primary vent structured to vent gas away from a vicinity of the primary contacts and into an area internal to the housing;
and
a secondary exhaust vent structured to vent gas away from the secondary contacts to an exterior of the housing,
wherein the primary contacts and the secondary contacts are in series,
wherein the PCB is configured such that, when the primary contacts are closed and the secondary contacts are closed, the PCB actuates the secondary actuator to open the secondary contacts simultaneously during thermal-magnetic opening of the primary contacts in response to detecting a fault condition exceeding a predetermined severity threshold.

10 more elements

Dependencies are inferred from the claim text.