US 9,520,254 B2Granted

Circuit interrupter including thermal trip assembly and printed circuit board Rogowski coil

AssigneeEaton Corporation

InventorsGerald Zheng, Jack Gu, Xin Zhou, Olina Ouyang, Bruce Wu

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Abstract

A circuit interrupter includes a first terminal, a second terminal, separable contacts moveable between a closed position and an open position, the first and second terminals being electrically disconnected from each other when the separable contacts are in the open position, a printed circuit board Rogowski coil structured to sense a current flowing between the first and second terminals, a current transformer structured to harvest power from the current flowing between the first and second terminals, an electronic trip unit including an other trip circuit structured to output a first trip signal to control the actuator to cooperate with an operating mechanism to trip open the separable contacts based on the current sensed by the current sensor and a thermal trip assembly structured to sense a temperature of a busbar and to output a second trip signal based on the sensed temperature.

Claims19

Dependent claims

A circuit interrupter comprising:

a first terminal;
a second terminal;
a plurality of busbars electrically connecting the first and second terminals;
separable contacts moveable between a closed position and an open position, the first and second terminals being electrically disconnected from each other when the separable contacts are in the open position;
an operating mechanism structured to open said separable contacts;
an actuator structured to cooperate with said operating mechanism to trip open said separable contacts;
a printed circuit board Rogowski coil structured to sense a current flowing between the first and second terminals;
a current transformer structured to harvest power from the current flowing between the first and second terminals;
and
an electronic trip unit including:
an other trip function circuit structured to output a first trip signal to control the actuator to cooperate with the operating mechanism to trip open the separable contacts based on the current sensed by the printed circuit board Rogowski coil;
and
a thermal trip assembly structured to sense a temperature of one of the plurality of busbars and to output a second trip signal based on the sensed temperature,
wherein one of the plurality of busbars includes a U-shaped section, and wherein the current transformer and the printed Rogowski coil encircle one side of the U-shaped section and the thermal trip assembly is disposed against another side of the U-shaped section.

11 more elements

A circuit interrupter comprising:

a first terminal;
a second terminal;
a plurality of busbars electrically connecting the first and second terminals;
separable contacts moveable between a closed position and an open position, the first and second terminals being electrically disconnected from each other when the separable contacts are in the open position;
an operating mechanism structured to open said separable contacts;
an actuator structured to cooperate with said operating mechanism to trip open said separable contacts;
a printed circuit board Rogowski coil structured to sense a current flowing between the first and second terminals;
a current transformer structured to harvest power from the current flowing between the first and second terminals;
and
an electronic trip unit including:
an other trip function circuit structured to output a first trip signal to control the actuator to cooperate with the operating mechanism to trip open the separable contacts based on the current sensed by the printed circuit board Rogowski coil;
and
a thermal trip assembly structured to sense a temperature of one of the plurality of busbars and to output a second trip signal based on the sensed temperature, wherein the thermal trip assembly comprises:
a fastener;
an insulating sleeve;
a temperature sensor structured to sense the temperature of one of the plurality of busbars;
and
a thermal trip circuit structured to output the second trip signal based on the sensed temperature,
wherein a portion of said insulating sleeve is disposed between the temperature sensor and said one of the plurality of busbars;
and
wherein the fastener couples the insulating sleeve and the temperature sensor to said one of the plurality of busbars with the insulating sleeve being in direct contact with a portion of said one of the plurality of busbars;
and
wherein the thermal trip circuit includes:
a temperature sensing circuit structured to output a voltage based on the temperature sensed by the temperature sensor;
a differential amplifier circuit structured to amplify to an output a difference between the voltage output by the temperature sensing circuit and a first predetermined voltage;
a follower circuit structured to buffer to an output a voltage of the output of the differential amplifier circuit;
an integrator circuit structured to smooth to an output a voltage of the output of the follower circuit;
and
a comparator circuit structured to compare a voltage of the output of the integrator circuit with a second predetermined voltage and to output the trip signal when the output of the integrator circuit is greater than the second predetermined voltage.

26 more elements

A circuit interrupter comprising:

a first terminal;
a second terminal;
a plurality of busbars electrically connecting the first and second terminals;
separable contacts moveable between a closed position and an open position, the first and second terminals being electrically disconnected from each other when the separable contacts are in the open position;
an operating mechanism structured to open said separable contacts;
an actuator structured to cooperate with said operating mechanism to trip open said separable contacts;
a printed circuit board Rogowski coil structured to sense a current flowing between the first and second terminals;
a current transformer structured to harvest power from the current flowing between the first and second terminals;
and
an electronic trip unit including:
an other trip function circuit structured to output a first trip signal to control the actuator to cooperate with the operating mechanism to trip open the separable contacts based on the current sensed by the printed circuit board Rogowski coil;
and
a thermal trip assembly structured to sense a temperature of one of the plurality of busbars and to output a second trip signal based on the sensed temperature, wherein the thermal trip assembly comprises:
a fastener;
an insulating sleeve;
a temperature sensor structured to sense the temperature of one of the plurality of busbars;
and
a thermal trip circuit structured to output the second trip signal based on the sensed temperature,
wherein a portion of said insulating sleeve is disposed between the temperature sensor and said one of the plurality of busbars;
and
wherein the fastener couples the insulating sleeve and the temperature sensor to said one of the plurality of busbars with the insulating sleeve being in direct contact with a portion of said one of the plurality of busbars,
wherein the thermal trip assembly further includes an ambient temperature sensor disposed apart from the busbar and structured to sense an ambient temperature;
and wherein the thermal trip circuit is structured to output the trip signal based on the sensed temperature of the busbar and the sensed ambient temperature, and
wherein the thermal trip circuit includes:
a temperature sensing circuit structured to output a voltage based on the temperature sensed by the temperature sensor;
a differential amplifier circuit structured to amplify to an output a difference between the voltage output by the temperature sensing circuit and a first predetermined voltage;
a follower circuit structured to buffer to an output a voltage of the output of the differential amplifier circuit;
an integrator circuit structured to smooth to an output a voltage of the output of the follower circuit;
an ambient temperature sensing circuit structured to output a voltage based on the ambient temperature sensed by the ambient temperature sensor;
an ambient differential amplifier circuit structured to amplify to an output a difference between the voltage output by the ambient temperature sensing circuit and a second predetermined voltage;
an ambient follower circuit structured to buffer to an output a voltage of the output of the ambient differential amplifier circuit;
an ambient integrator circuit structured to smooth to an output a voltage of the output of the ambient follower circuit;
an ambient output circuit structured to buffer to an output a voltage of the output of the ambient integrator circuit;
and
a comparator circuit structured to combine a voltage of the outputs of the integrator circuit and the ambient output circuit, to compare a voltage of the combined outputs of the integrator circuit and the ambient output circuit with a third predetermined voltage, and to output the trip signal when the combined outputs of the integrator circuit and the ambient output circuit are greater than the third predetermined voltage.

32 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/312,994Filed 24 Jun 2014
Published: US 2015/0371798 A124 Dec 2015
Granted: 13 Dec 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification16 codes

H01H 37/002
Thermally-actuated switches: combined with protective means
H01H 71/125
Using a solid-state trip unit: characterised by sensing elements, e.g. current transformers
H01H 73/20
Details: terminals; Connections
H02H 1/0007
Details of emergency protective circuit arrangements: concerning the detecting means