Patent Application
20220406549
This invention is directed generally to circuit breakers and, more particularly, to remote control of a miniature circuit breaker to connect or disconnect electrical power by remote control or alternately to interrupt electrical power in response to a trip fault.
Circuit breakers are conventionally used to protect electric power distribution circuits against arcing faults, ground faults, short circuit faults, and/or overloads. Typically, miniature circuit breakers are used particularly to protect branch circuits in homes and in commercial and light industry applications. Banks of miniature circuit breakers are typically arranged in an electrical panel for manual switching of power to respective branch circuits. When an electrical utility outage occurs, critical loads such as pumps, security systems, refrigerators and electronics should ideally have an auxiliary source of power available. In residential and in commercial and light industry applications, back-up generators or photovoltaic systems with battery back-up are available to provide limited auxiliary power, which is typically at a lower power level than is available from the utility. When a utility outage occurs, some means is required to switch the reduced auxiliary power to the critical loads. A homeowner or manager of a commercial or light industry facility may be located at some distance from the power switching panels and may need to travel to the site of the panels to manually switch over to the auxiliary power.
When a major power outage occurs for an electrical utility, such as due to a severe weather event, the utility may have to impose controlled rolling cutoffs of electric service in an area by area sequence, because the demand for power in the region overwhelms the available generation. Such controlled rolling cutoffs, even for a few hours in each affected area, imposes a total blackout to each home or business and a risk to critical loads during the length of the outage. The ability of the electrical utility to remotely provide limited reserve power to branch circuits connected to critical loads in homes or businesses, would mitigate the damage typically incurred from controlled rolling cutoffs.
In an existing miniature circuit breaker, the existing trip lever includes a transverse tab that is integral with the trip lever, which kicks the blade in response to a trip event, to open the main contacts. In order to adapt a miniature circuit breaker to include a motor or other prime mover to drive the main contacts under remote control, problems arise in adding a secondary set of contacts, including cost, packaging, bi-stable latching designs, current withstand capability, and more. In arc fault (CAFI) circuit breakers, there is not sufficient room for an extra link between a motor and the blade, since the mechanism is thin and room is already allocated to other parts. Locating the blade in other locations within the miniature circuit breaker risks pollution, debris, or melted geometry, causing the blade or blade acting parts to jam up and not work.
What is needed, therefore, is a way for the trip lever to automatically interrupt current in response to a trip event or alternately to open or close the main contacts under remote control.
In accordance with one example embodiment described herein, a modified trip lever for a remote controlled miniature circuit breaker performs alternate functions to either automatically open the main contacts in response to a trip event or alternately open or close the main contacts under remote control.
A kicker lever mounted on a pivot is configured to rotate clockwise in response to a remote control open signal, to open the main contacts by forcing a transverse tab on the kicker lever against a blade carrying a moveable main electrical contact aligned with a stationary main electrical contact. The kicker lever is configured to rotate counterclockwise to close the contacts in response to a remote control close signal.
A separate trip lever mounted on the same pivot as the kicker lever, is configured to automatically open the contacts in response to a trip event, by pushing against the back side of the transverse tab of the kicker lever. This causes the transverse tab to move in concert with the trip lever to push the front side of the transverse tab against the blade, to automatically open the contacts in response to the trip event.
In accordance with one example embodiment described herein, a modified trip lever for a remote controlled miniature circuit breaker, comprises:
a kicker lever pivotally mounted on a pivot in a housing of a miniature circuit breaker, having a first end and a second end on opposite sides of the pivot mounting of the kicker lever, with a transverse tab on the first end thereof configured to push a pivoted blade having a moveable main electrical contact that is aligned with a stationary main electrical contact mounted in the housing, to separate the moveable main contact from the stationary main contact, in response to an external control signal to open the main contacts; and
a trip lever pivotally mounted on the same pivot as the kicker lever, configured to push against the transverse tab of the kicker lever to cause the transverse tab to move in concert with the trip lever to push the pivoted blade, to separate the moveable main contact from the stationary main contact, in response to a detection of a trip event by the miniature circuit breaker.
In accordance with one example embodiment described herein, the modified trip lever for a remote controlled miniature circuit breaker, further comprises:
the kicker lever being configured to rotate counterclockwise about its pivot when the main contacts are in the open position, so that the transverse tab of the kicker lever relieves pressure on the blade, and the blade is thereby forced by a blade spring bias to the closed position for the main contacts.
The resulting apparatus and system enables a modified trip lever in a miniature circuit breaker to perform alternate functions to either automatically open the main contacts in response to a trip event or alternately enable an actuator in the circuit breaker to open the main contacts under remote control. Examples of an actuator may include a motor, a solenoid, a spring, a pneumatically or hydraulically actuated piston, or other prime mover.
A more detailed description of the disclosure, briefly summarized above, may be had by reference to various embodiments, some of which are illustrated in the appended drawings. While the appended drawings illustrate select embodiments of this disclosure, these drawings are not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.
A kicker lever 108 is pivotally mounted on the pivot 111 in the housing and shares the same pivotal mounting 111 with the trip lever 105. In a miniature circuit breaker without the remote control function of an example embodiment of the disclosure, a trip lever 105′ (
In accordance with an example embodiment of the disclosure, the kicker function is broken out into a separate trip function that is activated to open the contacts in response to a trip event. The separate, remote control function to open the main contacts in response to an external control signal, is enabled by the kicker lever 108 of an example embodiment of the disclosure.
In an example embodiment of the disclosure, the kicker lever 108 has a first end 110 and a second end 112 (
A slider plate 120 is slidably mounted in the housing 113, and has an end surface 122 configured to push against the second end 112 of the kicker lever 108 to open the main contacts 102, 102′, when the slider plate 120 moves toward the left, as shown in transitioning from the closed position in
To close the main contacts 102, 102′, as shown in transitioning from the open position in
An actuator 150 is mounted in the housing 113, configured to drive the slider plate 120. Examples of an actuator 150 may include an electric motor, a solenoid, a spring, a pneumatically or hydraulically actuated piston, or other prime mover. When an external control signal is received to close the main contacts 102, 102′, from their open position shown in
An electrical position switch 152 mounted in the housing 113 is connected to a microcontroller 200 (
After the microcontroller receives an open command to open the main contacts 102, 102′, the microcontroller energizes the actuator 150 to push the slider plate 120 and force the slider plate 120 to move leftward away from the actuator 150. The end surface 122 of the slider plate 120 moves toward and pushes against the second end 112 of the kicker lever 108, causing the kicker lever 108 to rotate clockwise. The clockwise rotation of the kicker lever 108 causes the transverse surface 110′ of the first end 110 of the kicker lever 108 to pivot against and push or kick the blade 104, to move blade 104 against the toggle spring 106 bias, from the closed position of
The resulting apparatus and system enables a miniature circuit breaker to connect or disconnect electrical power by remote control or alternately to interrupt electrical power in response to a trip fault.
In the preceding, reference is made to various embodiments. However, the scope of the present disclosure is not limited to the specific described embodiments. Instead, any combination of the described features and elements, whether related to different embodiments or not, is contemplated to implement and practice contemplated embodiments. Furthermore, although embodiments may achieve advantages over other possible solutions or over the prior art, whether or not a particular advantage is achieved by a given embodiment is not limiting of the scope of the present disclosure. Thus, the preceding aspects, features, embodiments and advantages are merely illustrative and are not considered elements or limitations of the appended claims except where explicitly recited in a claim(s).
The various embodiments disclosed herein may be implemented as a system, method or computer program product. Accordingly, aspects may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “component”, “circuit,” “module” or “system.” Furthermore, aspects may take the form of a computer program product embodied in one or more computer-readable medium(s) having computer-readable program code embodied thereon.
Any combination of one or more computer-readable medium(s) may be utilized. The computer-readable medium may be a non-transitory computer-readable medium. A non-transitory computer-readable medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the non-transitory computer-readable medium can include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. Program code embodied on a computer-readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
Computer program code for carrying out operations for aspects of the present disclosure may be written in any combination of one or more programming languages. Moreover, such computer program code can execute using a single computer system or by multiple computer systems communicating with one another (e.g., using a local area network (LAN), wide area network (WAN), the Internet, etc.). While various features in the preceding are described with reference to flowchart illustrations and/or block diagrams, a person of ordinary skill in the art will understand that each block of the flowchart illustrations and/or block diagrams, as well as combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer logic (e.g., computer program instructions, hardware logic, a combination of the two, etc.). Generally, computer program instructions may be provided to a processor(s) of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus. Moreover, the execution of such computer program instructions using the processor(s) produces a machine that can carry out a function(s) or act(s) specified in the flowchart and/or block diagram block or blocks.
The flowchart and block diagrams in the Figures illustrate the architecture, functionality and/or operation of possible implementations of various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other implementation examples are apparent upon reading and understanding the above description. Although the disclosure describes specific examples, it is recognized that the systems and methods of the disclosure are not limited to the examples described herein but may be practiced with modifications within the scope of the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative sense rather than a restrictive sense. The scope of the disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
