BUS BYPASS OVERCURRENT PROTECTION
Devices and methods are described for connecting an alternative energy source (for example, solar, wind, or gas generator power) to power source lines of a utility company to back-feed power to the utility company at a circuit breaker panel. In some implementations, an over current protection device (OCPD) is electrically coupled to the source lines before the source lines are coupled to the main circuit breaker such that it can pass current from the alternative energy source to the source lines without using the busbars of the circuit breaker panel. In some implementations, the OCPD includes slots that are configured to receive the source lines when the OCPD is pushed down over the source lines. The OCPD also includes coupling structures that fit around at least a portion of the source lines, and includes one or more spike taps to electrically couple to the source lines.
This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 62/124,773, filed Jan. 2, 2015, which is hereby expressly incorporated by reference herein.
FIELDThis disclosure relates to devices for connecting alternative energy sources to source lines of a utility company. More specifically, this disclosure relates to devices that electrically couple to source lines in a circuit breaker panel to transfer power to the source lines without using busbars of the circuit breaker panel.
BACKGROUNDIf a homeowner decides to invest in an alternative energy system (for example, rooftop-installed solar panels) with the goal of back-feeding energy to a utility, one must choose between one of two currently available options/approaches: a line-side (or supply-side, or utility-side) tap or a meter bypass. The conventional line-side tap approach is certainly the most expensive and time-consuming of these two options, but the meter bypass approach also suffers considerably by comparison with the instant invention.
For conventional line-side tapping, the homeowner must have an employee of the utility company come to their house and literally cut the power lines (120 VAC A- and B-phases and the neutral line) feeding the service panel prior to the utility meter for the home. The meter is then pulled out and connections, for example using connectors such as a KUP-L-TAP®, are made to the two 120 VAC lines below/behind the meter.
Once both of the 120 VAC lines have been tapped, each tap must be thoroughly wrapped in electrical tape resulting in large tape-wrapped taps. Power from the utility to the meter cannot be restored until an inspector from Underwriters Laboratory (UL) visits the site, inspects the taps, and deems them as having been properly installed in compliance with UL standards. (This is mandated because the main panel was not originally designed or tested to operate with lines that have KUP-L-TAP®-type connections. It may cost upwards of $3,300 to have a UL representative perform this inspection and, assuming all is in order, approve the taps. At this point, the homeowner has a document from UL certifying that the taps are UL compliant. This document must then be provided to the local utility company having jurisdiction, and the homeowner calls an employee of the utility to come back to the home, reconnect the lines, and reinsert the utility meter. The homeowner is typically without power for an entire day. Accordingly, a conventional line-side tap approach entails a considerable amount of time, effort, and expense.
The only other option currently available to homeowners interested in back-feeding alternative energy to the grid has been to bypass the utility meter. One device to bypass the meter is shown in U.S. Pat. No. 8,784,130, which describes an electrician pulling the utility meter, coupling a base meter adapter to the service panel, and then re-inserting the original utility meter into the meter adapter. Disadvantages of this approach are the cost of the components and labor needed for this installation, that the meter must be pulled, and the need to have additional components mounted on a wall. In addition, the resulting base meter adapter and utility meter combination present a rather considerable profile/lever arm that might prove alluring to playful children, who as a result may be tempted to place their hands and arms around the combination and dangle therefrom, resulting in the combination being pulled out and exposing them to full line voltage present in the jaws behind the meter.
SUMMARYThe systems, methods and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.
Some innovations relate to a back feed device, also referred to herein as an over current protection device (“OCPD”) for electrically coupling at least one power source line (for example, coupling two source lines each providing 120VAC phase power) in a circuit breaker panel to an alternative power source at a location before the source lines connect to a main circuit breaker in the circuit breaker panel. The source lines connected to a main circuit breaker in the circuit breaker panel and each providing power to the circuit breaker panel, to provide an electrical connection between the alternative power source and the power source lines that does not use busbars of the circuit breaker panel for the electrical connection. In some implementations the device includes means for electrically coupling including a first means for electrically coupling to a first source line configured to carry 120VAC phase A and a second means for electrically coupling to a second source line configured to carry 120VAC phase B power with two electrically distinct connections, the means for electrically coupling configured to be placed at least partially around the first and second source lines without cutting or disconnecting the first and second source lines, the means for electrically coupling configured to couple to the first and second source line at a location adjacent to the main circuit breaker in a circuit breaker panel and before the first and second source lines connect to the main circuit breaker, terminals for connecting to an alternative power source, the terminals including at least a first terminal and a second terminal, and means for protecting for an over-current condition electrically connected between the terminals and the means for electrically coupling.
Such a device may include additional aspects (e.g., features) in various embodiments. In some embodiments, the means for electrically coupling includes a threaded slot connector having a slot that allows one of the source lines to pass through the slot and be disposed within the interior of the threaded slot connector, the threaded slot connector having external threads and having at least one tapping spike disposed in the interior of the threaded slot collector, and a slotted nut having a slot that allows one of the source lines to pass through the slot and be disposed within the interior to the slotted nut, the slotted nut fitting onto the exterior threads of the threaded slot connector, the slotted nut and the threaded clot connector collectively configured to move the at last one tapping spike to electrically couple to a source line within the threaded slot connector when the slotted nut is wound onto the threaded slot connector. In some embodiments, the threaded slot connector comprises a tapered shape that deforms when the slotted nut is wound onto the exterior threads to push the at least one tapping spike into the source line. In some embodiments, the means for protecting for an over-current condition comprises at least one fuse. In some embodiments, the means for protecting for an over-current condition comprises at least one circuit breaker that is not directly electrically connected to a busbar of the circuit breaker panel.
In some embodiments, the means for coupling include two sets of one or more tapping spikes, each set of the one or more tapping spikes for electrically connecting to one of the first and second source lines. In some embodiments, the means for electrically coupling comprises two sets of one or more tapping spikes, each set of the one or more tapping spikes arranged to at least partially surround one of the source lines when the means for coupling is placed on the source lines, configured to deform to move the one or more tapping spikes to be electrically coupled to the at least partially surrounded source line when the means for coupling is crimped around the source lines. In some embodiments, the means for protecting for an over-current condition comprises at least one fuse or at least one circuit breaker. In some embodiments, the means for electrically coupling comprises a source line receptacle configured to at least partially surround a source line passing through the means for electrically coupling, the source line receptacle including at least one tapping spike, a clamping structure disposed along a lower portion of the source line receptacle to secure a source line in the source line receptacle; and at least one connector coupled to the clamping structure and disposed to be actuated from an upper surface of the device, the connector extending from the upper surface of the device to the clamping structure, the connector and clamping structure collectively configured to move the clamping structure to a closed position to secure a source line into the source line receptacle and electrically coupling the at least one tapping spike to the source line when the clamping structure is moved to the closed position.
In some embodiments, the first means for electrically coupling includes a first source line receptacle configured to at least partially surround the first source line when the device is disposed over the first source line so that the first source line passes through the means for electrically coupling, the first source line receptacle including at least one tapping spike, a first clamping structure disposed along a lower portion of the first source line receptacle to secure a source line in the first source line receptacle; at least one first connector coupled to the first clamping structure and disposed to be actuated from an upper surface of the device, the at least one first connector extending from the upper surface of the device to the first clamping structure, the at least one first connector and the first clamping structure collectively configured to move the first clamping structure to a closed position to secure the first source line into the first source line receptacle electrically coupling the at least one tapping spike to the first source line when the first clamping structure is moved to the closed position. In some embodiments, the second means for electrically coupling includes a second source line receptacle configured to at least partially surround the second source line when the device is disposed over the second source line so that the second source line passes through the means for electrically coupling, the second source line receptacle including at least one tapping spike, a second clamping structure disposed along a lower portion of the second source line receptacle to secure a source line in the second source line receptacle, and at least one second connector coupled to the second clamping structure and disposed to be actuated from an upper surface of the device, the at least one second connector extending from the upper surface of the device to the second clamping structure, the at least one second connector and the second clamping structure collectively configured to move the second clamping structure to a closed position to secure the second source line into the second source line receptacle electrically coupling the at least one tapping spike to the second source line when the second clamping structure is moved to the closed position. In some embodiments, the means for protecting for an over-current condition comprises at least one fuse or at least one circuit breaker. In some embodiments, the device further includes a power transfer bar electrically coupled to the means for electrically coupling and extending generally perpendicular to the first and second source lines to fit adjacent to one of more circuit breakers disposed beside the main circuit breaker, the power transfer bar including a first conductive bus electrically coupled to the first means for electrically coupling and to the first terminal, and a second conductive bus coupled to the second means for electrically coupling and the second terminal.
Another innovation includes a device for electrically coupling a first source line carrying 120VAC phase A power and a second source line carrying 120VAC phase B power to an alternative power source to feed power from the alternative power source to the first and second source lines without using busbars of a circuit breaker panel, the first and second source lines providing power to a main circuit breaker in a circuit breaker panel, the device including a source line coupler configured to couple to the first source line and the second source line in a circuit breaker panel at least partially around the first and second source lines without cutting or disconnecting the first and second source lines, the source line coupler including an entry portion and an exit portion having openings for the two source lines to pass thru the source line coupler when the device is placed on the first and second source line such that the exit portion is proximate to the main circuit breaker and the entry portion is distal to the main circuit breaker, the source line coupler including a first source line receptacle for receiving the first source line when the device is placed over the first source line such that the first source line is disposed in the first line receptacle, the first source line receptacle including at least one first conductive tapping spike disposed to contact the first source line when the first source line is secured in the first source line receptacle, a second source line receptacle for receiving the second source line when the device is placed over the second source line such that second source line is disposed in the second line receptacle, the second source line receptacle including at least one second conductive tapping spike disposed to contact the second source line when the second source line is secured in the second source line receptacle, terminals for connecting to an alternative power source, the terminals including at least a first terminal and a second terminal, and a first over-current protector and a second over-current protector that stop current from flowing at a predetermined threshold level, the first over-current protector electrically connected between at least one first tapping spike and the first terminal, and the second over-current protector electrically coupled between the at least one second tapping spike and the second terminal.
Such a device may include additional aspects (e.g., features) in various embodiments. In some embodiments, the first and second over-current protectors are fuses. In some embodiments, the first and second over-current protectors are circuit breakers. In some embodiments, the device further includes a power transfer bar electrically coupled to the source line coupler and extending generally perpendicular to first and second source lines that are secured in the source line coupler, the power transfer bar configured to fit adjacent to one of more circuit breakers disposed beside the main circuit breaker, the power transfer bar including a first conductive bus electrically coupled between the at least one first tapping spike and the first terminal, and a second conductive bus electrically coupled between the at least one second tapping spike and the second terminal second means for electrically coupling and the second terminal. In some embodiments, the source line coupler includes a first clamping structure disposed along a portion of the first source line receptacle to secure the first source line in the first source line receptacle; and at least one connector coupled to the first clamping structure and disposed to be actuated from an upper surface of the device, the connector extending from the upper surface of the device to the first clamping structure, the connector and first clamping structure collectively configured to move the clamping structure to a closed position to secure the first source line into the first source line receptacle and electrically couple the at least one first tapping spike to the first source line when the first clamping structure is moved to the closed position. In some embodiments, the first clamping structure is coupled to two connectors disposed to be actuated from the upper surface of the device, the two connectors extending from the upper surface of the device to the first clamping structure and coupled to the first clamping structure. In some embodiments, the first clamping structure is configured to be adjusted using one or more of the two connectors coupled to the first clamping structure to change the size of the first source line receptacle.
Another innovation includes a method for installing a device to back feed energy from an energy source to source lines in a preexisting circuit breaker panel. In some embodiments the method includes inserting a back feed device in a circuit breaker panel between a main circuit breaker and a utility meter, the back feed device dimensioned to couple to a first source line and a second source line and be disposed within the circuit breaker panel. The back feed device includes a source line coupler configured to couple to the first source line and the second source line and at least partially around the first and second source lines, the source line coupler including a first source line receptacle for receiving the first source line such that the first source line is disposed in the first line receptacle, the first source line receptacle including at least one first conductive tapping spike disposed to contact the first source line when the first source line is secured in the first source line receptacle, a second source line receptacle for receiving the second source line, the second source line receptacle including at least one second conductive tapping spike disposed to contact the second source line when the second source line is secured in the second source line receptacle. The back feed device further includes terminals for connecting to an alternative power source, the terminals including at least a first terminal and a second terminal, and a first over-current protector and a second over-current protector that stop current from flowing at a predetermined threshold level, the first over-current protector electrically connected between the at least one first tapping spike and the first terminal, and the second over-current protector electrically coupled between the at least one second tapping spike and the second terminal. The method may also include coupling the source line coupler to the first source line and the second source line.
Another innovation includes a circuit breaker including a first connector configured to connect to a first busbar supplying power to the breaker in a first phase, a second connector configured to connect to a second busbar supplying power to the breaker in a second phase, a first bimetallic strip in thermal connection with the first busbar, and a second bimetallic strip in thermal connection with the second busbar, the first and second bimetallic strips configured to deform and interrupt the connections between the breaker and the first and second busbars if either of the first or second bimetallic strips exceed a threshold temperature.
In some embodiments, the first bimetallic strip can form a part of the electrical connection between the first busbar and the breaker. In some embodiments, the second bimetallic strip can form a part of the electrical connection between the second busbar and the breaker. In some embodiments, the circuit can additionally include a linking member configured to engage or retain a portion of the first bimetallic strip and a portion of the second bimetallic strip, where displacement of the first bimetallic strip displaces the linking member and the second bimetallic strip. In some embodiments, the linking member can include a first notch configured to retain a portion of the first bimetallic strip and a second notch configured to retain a portion of the second bimetallic strip, where the width of the first and second notches is less than the travel ranges of the first and second bimetallic strips. In some embodiments, the circuit breaker can additionally include a reset member configured to displace the linking member to move the first and second bimetallic strips to a reset position.
Another innovation includes a power transfer structure, including a first section configured to retain a portion of a first power line, a second section configured to retain a portion of a second power line and place the second power line in electrical communication with the first power line, and a bimetallic strip in thermal contact with at least one of the first or second power lines and configured to deform and interrupt the electrical communication between the first power line and the second power line if the temperature of the bimetallic strip exceeds a threshold temperature.
In some embodiments, the bimetallic strip can form part of an electrical connection between the first power line and the second power line. In some embodiments, the first section can be configured to expose and contact a conductive portion of the first power line and wherein the second section is configured to expose and contact a conductive portion of the second power line. In some embodiments, the first section can include an electrical lug and a clamping screw. In some embodiments, the first section can include a tapping spike. In some embodiments, the second section can include an electrical lug and a clamping screw. In some embodiments, the second section can include a tapping spike. In some embodiments, the bimetallic strip can be linked to a second bimetallic strip in another power transfer structure configured to form an electrical connection between a third power line and a fourth power line, where deformation of the bimetallic strip induces deformation of the second bimetallic strip.
Certain inventive aspects will hereinafter be described in conjunction with the appended drawings, provided to illustrate and not to limit the disclosed aspects. In these figures, reference numerals are generally used to indicate the same component, however, various configurations of an indicated component may all be referred to using the same reference numeral for clarity of the description. In some figures, components that are indicated by a reference numeral, and that also are illustrated in other figures, may not be described each time for clarity of the disclosure, and in such cases other description of such commonly referenced components in other implementations may apply, unless indicated otherwise, explicitly or by context.
Embodiments of the disclosure relate to systems and techniques for implementing devices and methods that can be used to electrically couple alternative energy sources to existing circuit breaker panels for residential and commercial implementations. The so-called “120% Rule” is a limiting factor, for solar designers and installers, in designing and installing a system to maximize solar production from residential homes as well as commercial structures, in that it limits the maximum power output threshold possible from a given solar system, without having to resort to other methodologies that are expensive and time intensive.
For many houses and businesses, the power source lines coming in to a house from an electric utility company are two phases of 120VAC (namely, phases “A” and “B”) and a neutral. These lines go through the utility meter, which, if one does not have an alternative energy source (e.g., solar panels) only spins forward, and one is charged based on the number of kilowatt hours (kWh) one consumes. After the wires go through the meter, they are routed to your 100 A or 200 A main service disconnect (aka main breaker). Note that some residences have 125 A, 400 A, etc., depending on the size and energy requirements of the home. For example, for a single family home (without a suite) having a gas furnace, a gas stove, and perhaps a gas water heater, 100 A typically is sufficient. On the other hand, if one is looking at a home that has a suite and, say, two electric washers and dryers, electric furnaces, electric stove(s), and one or more electric vehicles, a sauna, etc., or a dwelling in a remote location that does not have natural gas service, then a 100 A panel will likely be strapped and need to be upgraded to 200 A.
The busbar rating in a residential service panel typically matches the rating/size of the main breaker. For example, a service equipped with a 100 A main breaker allows 100 A of current to be provided to the busbar—that is, the main breaker will trip if more than 100 A is presented to the busbar. By NEC code (the “120% Rule”), a breaker connected to an alternative energy system must be installed at the opposite end (usually the bottom) of the busbar from the end (typically the top) at which the main breaker is installed.
The available above-described available approaches for connecting alternative energy systems to main service panels include many issues. For example, the comparative high cost (w/r/t conventional line-side tapping) scheduling issues (i.e., arranging when various individuals from different entities can meet at the home/install site), indefiniteness of work schedules (as inspectors routinely quote three-hour windows during which they may show up), time that a given electrician has to be on site, etc. The OCPDs described herein eliminate many, if not all, of such issues, perhaps most notable being because the busbar is bypassed, the 120% rule does not have to be observed, thereby allowing the installation of arbitrarily large alternative energy systems.
The various embodiments disclosed in the instant application can be implemented without turning off power to the main panel. That is, each embodiment is installed by the live tapping of both phases (A and B) of incoming 120VAC line power (and, of course, three-phases in commercial applications). The OCPD devices, may simply be connected manually (in some cases without tools) to the power coming into the main breaker (for either two- or three-phase applications), literally pushed down over the conductors and either threadably engaged, crimped on, or clamped tightened to establish electrical contact with the main power.
The electrical configuration illustrated in
busbar rating (100 A)×120%−minus the main breaker rating (100 A)=20 A
This means you're able to back-feed 20 A from an alternative electrical source, provided that the alternative energy breaker 39 is on the opposite end of the busbar. Accordingly, as illustrated in
In various configurations of OCPD's 11 described herein, the source lines pass physically through a portion of the OCPD 11, for example, the source line 4a, 4b pass through and/or past, partially or wholly, electrical coupling means (or structure) of the OCPD 11 that electrically couple the OCPD to the source lines 4a, 4b. That is, the OCPD 11 is connected to the source lines 4a, 4b and to an alternative power source (not shown in this illustration). Other configurations of OCPD's 11 are described herein, each having certain aspects that may be advantageous to use in certain installations and implementations. One advantage of implementations of the OCPD 11 is that it can be safely installed without disconnecting power in the source lines 4a, 4b, for example, without pulling the utility meter 3 to disconnect power to the source lines 4a, 4b. Another advantage of implementations of the OCPD 11 is that the source lines 4a, 4b do not have to be severed or disconnected from the main circuit breaker 3. Another advantage of implementations of the OCPD 11 is that it is configured to entirely with dimensions to fit into a circuit breaker panel 3 (for example, as illustrated). Implementations of the OCPD 11 where it is housed completely within the circuit breaker panel 3 outer walls and door provide security and electrical safety, and it also provides an aesthetically pleasing installation that does not need additional boxes and connections that are outside of the circuit breaker panel 2. Other configurations of systems that tap into source lines 4a, 4b that require installation of one or more additional electrical boxes outside of the circuit breaker panel 2, and electrical lines connecting the additional electrical boxes to the source lines may be more costly due the need for more components and may require labor intensive processes to properly connect them, increasing installation costs.
In various implementations described herein, the OCPD 11 may include one or more fuses, one or more breakers, or both, to ensure the electrical safety of the alternative power source connection and to meet any relevant electrical standards/codes. A s used herein, the term “over-current protector” may generally refer to either a fuse or a circuit breaker. OCPD 11 is configured to be installed without turning off the power in source lines 4a, 4b. In the particular implementation illustrated in
The OCPD 11 includes two threaded slot connectors 47 and two slotted nuts 14 that are sized to wind over the threaded slot connectors 47. As shown in the example of
The slotted thread connectors 47 have a tapered configuration (
The OCPD 11 also includes two electrical terminals 18 for connection to, and to receive power from, an alternative electrical source connected to the terminals 18. The terminals 18 are electrically coupled to the source lines 4a, 4b when the OCPD 11 is coupled to the source lines 4a, 4b via the one or more tapping spikes 12. Fuses 22 are electrically connected in serial between a source line 4a, 4b and a terminal 18 such that power provided to the OCPD 11 from an alternative electrical source goes through one of the fuses. In the implementation illustrated in
As illustrated in
As illustrated in
The OCPD 11 illustrated in
In these implementations, the OCPD 11 is coupled to the source lines 4a, 4b using a means for electrical coupling, for example, but not limited to, one of the examples of means for electrical coupling (for example, threaded slot connectors 47 and threaded slot nuts 14, crimp couplers 67 with tapping spikes 12, upper and lower clamping structure 130, 129, screw-down bolt style, etc.). Other means of electrical coupling the OCPD 11 to the source lines 4a, 4b may also be used. Examples of the various implementations of means for coupling the OCPD 11 to the source lines 4a, 4b are shown in
The power transfer bar 24 includes an electrical bus for providing power passing through the circuit breaker 23 to the source lines 4a, 4b, via a coupling means. In typical embodiments the power transfer bar 24 includes two electrical busses to each provide power to one of source lines 4a and 4b. The power transfer bar 24 of the alternative energy feed-back device OCPD 11 includes two electrical busses to provide electrical connections between the electrical coupling means that is coupled to the source lines 4a, 4b and the terminals 18 for connecting to the alternative energy source. The terminals 18, the power transfer bar 24, and the coupling mechanism to the source lines 4a, 4b provide an electrical path to provide power back to the meter 1 and the utility company without passing the current from the alternative power source through one of the busbars 5a, 5b. In particular, the electrical path for power from alternative energy source fed back to the meter 1 may be from the alternative energy source to terminals 18, through circuit breaker 23 to the power transfer bar 24, through electrical busses of the power transfer bar 24 to the source line coupler and to the source lines 4a, 4b for example through spiking taps 12. Circuit breaker 23 may be disposed on the busbars 5a, 5b for stability but the circuit breaker 23 is not directly electrically connected (or electrically clipped) to the busbars 5a, 5b such that power from an alternative energy device that is fed back through terminals 18 does not pass through the busbars 5a, 5b. In some implementations, circuit breaker 23 is a regular is configured for the electrically connecting to the busbars 5a, 5b. In such cases, the power transfer bar 24 may also be configured to block the electrical connections between circuit breaker 23 and busbars 5a, 5b. For example, the power transfer bar 24 is configured to extend under or alongside at least a portion of circuit breaker 23, and further configured such that the circuit breaker 23 electrically connects to a portion of the power transfer bar 24 connecting the busses of the power transfer bar 24 to the circuit breaker 23. In such embodiments, the electrical busses of the power transfer bar 24 connect to power input terminals on the breaker 23 (which may be the input terminals that are normally electrically connected to the busbars 5a, 5b).
Example of the power transfer bar 24 are illustrated in
Additional aspects of the illustrated OCPD 11 are illustrated in
The circuit breaker 23 may be physically connected to one or more of the busbars 5a, 5b for stability purposes but does not transfer power through the busbars 5a, 5b. The OCPD 11 of
A bimetallic strip can be used to convert a temperature change into a mechanical displacement. The bimetallic strip is a structure in which the amount and/or direction of curvature is dependent upon the temperature of the device. The bimetallic strip 30 includes at least first and second metallic strips which are secured relative to one another. The first metallic strip includes a first material having a first coefficient of thermal expansion and the second metallic strip includes a second material having a second coefficient of thermal expansion which is greater than the first coefficient of thermal expansion of the first material. The first and second metallic strips may be secured relative to one another at multiple points along their length, by means such as brazing, welding, or rivets. Any other suitable securing means may also be used. In some embodiments, the first material may include steel and the second material may include copper or brass. However, any suitable pair of materials may be used.
Depending on the particular design of the bimetallic strip 30, the range of curvature over a range of temperatures may or may not include a temperature at which the curvature of the bimetallic strip is essentially zero. In some embodiments, a section of the bimetallic strip 30 may be configured to transition through a substantially planar state when the bimetallic strip 30 is at a specific temperature. In other embodiments, at least a portion of the bimetallic strip 30 may be configured to remain in a concave shape until a threshold temperature is reached, at which point the strain induced by differential expansion of the first and second metal layers causes the concave portion of the bimetallic strip to snap to a convex shape, reversing the direction of curvature of that portion of the bimetallic strip. In other embodiments, the bimetallic strip 30 may be in the form of a coil, rather than a semi-linear strip, and changes in temperature will tighten or relax the coil. The use of a coiled bimetallic strip can increase the sensitivity of the bimetallic strip structure to temperature changes.
As the temperature of the bimetallic strip 30 increases, the second metallic strip will expand at a rate greater than the first metallic strip. Thus, in some embodiments, the bimetallic strip 30 at higher temperatures will be curved such that the second metallic strip, which has the higher coefficient of thermal expansion, is on the outer side of the curve or coil. In other embodiments, where the bimetallic strip 30 is curved such that the second metallic strip is on the interior side of the curve or coil, increasing the temperature can reduce the curvature or while the second metallic strip remains on the interior side of the curve or coil.
In the illustrated embodiment, the bimetallic strip 30 can be configured such that the central portion of the bimetallic strip 30 bulges towards the lugs 31 at safe operating temperatures, holding the contacts 34 at the ends of the bimetallic strip 30 in contact with the facing contacts 34 on the electrical lugs 31 (see
Because the bimetallic strip 30 is a thermally conductive structure in contact with the source line 4a and the bypass power line 40a, the temperature of the bimetallic strip 30 will quickly reach and remain at a temperature close to that of the source line 4a and the bypass power line 40a. Thus, the bimetallic strip 30 can provide an almost immediate response to elevated temperatures, which represent a significant fire hazard. This response can be faster than the response of circuit breakers which trigger based on excessive amperage across the breaker, as such circuit breakers can experience a delay before triggering. The use of bimetallic strips 30 as described herein can provide a supplemental safety precaution against fire risk from elevated temperatures. In the particular embodiment illustrated in
In the illustrated embodiment, the bimetallic strip 30 forms a part of the circuit connecting the source line 4a to the bypass power line 40a. Flexure of the bimetallic strip 30 sufficient to separate at least one of the contacts 34 of the bimetallic strip 30 from the facing contact 34 of an electrical lug 31 will interrupt the circuit, and disconnect the source line 4a to the bypass power line 40a. In other embodiments, however, a bimetallic strip 30 in contact with at least one of the source line 4a and the bypass power line 40a can be used to directly or indirectly cause displacement of a separate conductive structure connecting the source line 4a and the bypass power line 40a, interrupting that connection. Thus, a bimetallic strip can be used to interrupt the connection between the source line 4a and the bypass power line 40a even without the bimetallic strip forming a part of the electrical circuit connecting the source line 4a and the bypass power line 40a.
A similar bimetallic strip safety feature can be included in the power transfer post connecting source line 4b to the bypass power line 40b. The bimetallic strips at each power transfer post can be arranged in series with one another, so that tripping of one of the bimetallic strips results in tripping of the other bimetallic strip, even if only one of the power transfer posts is experiencing overheating. One possible structure for triggering the tripping of the other bimetallic strip is discussed with respect to
In addition to the use of bimetallic strips at the power transfer posts, bimetallic strips can also be used as safety features within the bypass breakers to monitor the temperature of the busbars.
The bypass breaker 11 also includes a second bimetallic strip 50b, which is also in a tripped position. A contact 54b on second spring clamp 57b is separated from a facing contact 57d of bimetallic strip 50b, due to the tripped positioning of the bimetallic strip 50b in which the central portion of the bimetallic strip 50b bulges away from second spring clamp 57b. The tripped positioning of the bimetallic strip 50b also results in a separation between bimetallic strip contact 54f, and a contact 54h on breaker component 157b.
A linking member 74 extends between bimetallic strip 50a and 50b. A channel 72 or other guide permits longitudinal translation of linking member 74 along the axis of the channel 72, while otherwise constraining translation of the linking member 74. The linking member includes a first notch 175a retaining bimetallic strip 50a, and a second notch 175b retaining bimetallic strip 50b. The width of notches 175a and 175b is less than the range of movement of the retained portions of bimetallic strips 50a and 50b between their tripped and untripped positions, such that movement of, for example, bimetallic strip 50a between an untripped and a tripped position results in longitudinal translation of the linking member 74 through the channel 72, and pulls the other bimetallic strip 50b to a tripped position as well, regardless of the temperature of the bimetallic strip 50b. This series arrangement of the bimetallic strips 50a and 50b ensures that both bimetallic strips 50a and 50b are tripped if the temperature of one of the strips 50a or 50b exceeds a threshold temperature.
The linking member 74 includes a cam surface 174 oriented at a first angle, and the reset arm 75 includes a facing cam surface 173 oriented at a second angle complementary to the first angle of the cam surface 174. When the reset button is pressed downward, axial translation of the reset bar causes the facing cam surface 173 of the reset arm 75 to engage with the cam surface 174 of the linking member 74, causing axial translation of the linking member 74 towards the spring clamps 57a and 57b. The axial translation of the linking member 74 causes the edges of notches 175a and 175b to push the bimetallic strips 50a and 50b into a reset, or untripped, position as shown in
When the bimetallic strip 50a is pushed back to the untripped position, the contact 54a on first spring clamp 57a is brought back into contact with the a facing contact 57c of bimetallic strip 50a, and the bimetallic strip contact 54e is brought back into contact with contact 54g on breaker component 157a, completing the connection between the first spring clamp 57a and breaker component 157a. Similarly, when bimetallic strip 50b is pushed back to the untripped position, the contact 54b on first spring clamp 57b is brought back into contact with the a facing contact 57d of bimetallic strip 50b, and the bimetallic strip contact 54f is brought back into contact with contact 54h on breaker component 157b, completing the connection between the first spring clamp 57b and breaker component 157b.
The steep angle of the cam surfaces allows for substantial travel of the reset button 71 to result in a smaller amount of travel of the linking member 74. This larger travel range of the reset button 71 can provide a clearer visual indication of the status of the bimetallic strips 50a and 50b in breaker 11, without requiring a similarly large travel range for the bimetallic strips 50a and 50b between their tripped and untripped statuses. In other embodiments, however, other angles can be used, or the reset button may be aligned with the linkage bar, such that cam surfaces to alter the direction of movement are not needed.
The use of bimetallic strips 50a and 50b as safety features in the bypass breaker 11 provides a rapid way to disconnect the bypass breaker 11 and associated alternative energy or other source from the busbars 5a and 5b if the busbars 5a and 5b begin to overheat, presenting a fire hazard. This provides a level of overcurrent protection which can be used in conjunction with other safety features, such as other features of the circuit breaker 11 or a main breaker, to provide supplemental protection against overheating and fire.
The use of a bimetallic safety strip as a safety feature can be used with or without a bypass system, as any main panel can be at risk of overheating and fire in the time period before a circuit breaker trips. Thus, these bimetallic safety strips can be installed in any breaker, or at other locations in or adjacent to a main panel. As discussed above with respect to the power transfer posts, the bimetallic strips 50a and 50b need not form a part of a circuit which transmits load from the busbars to the bypass breakers, but instead may directly or indirectly trigger motion of another component to break a circuit if the bimetallic strip reaches a threshold temperature. Although some examples of bimetallic strips are described and depicted herein as curved strips which snap from a first position to a second position with opposite curvature, other designs may also be used. These alternative designs include coils, as well as structures and designs which undergo more gradual transitions when a temperature threshold is reached.
The alternative energy breaker also includes a bimetallic strip 50 which may be configured as an alternative trigger to the alternative energy breaker, in case the components begin to overheat even when the sensor relay 80 is not triggered. Breaker spring 76 can be used to keep pressure in releasing the bimetallic strip 50. Wire 77 is used to transfer power from the bimetallic strip 50 to the contact arm of the breaker, which supports a contact 54. Curvature induced in the bimetallic strip 50 when a threshold temperature is exceeded will trigger the alternative energy breaker, breaking the circuit and cutting off the alternative power input 18 from the main power busbars.
Implementations disclosed herein provide systems, methods and apparatus for local intensity equalization in region matching techniques. One skilled in the art will recognize that these embodiments may be implemented in hardware, software, firmware, or any combination thereof.
In some embodiments, the circuits, processes, and systems discussed above may be utilized in a wireless communication device. The wireless communication device may be a kind of electronic device used to wirelessly communicate with other electronic devices. Examples of wireless communication devices include cellular telephones, smart phones, Personal Digital Assistants (PDAs), e-readers, gaming systems, music players, netbooks, wireless modems, laptop computers, tablet devices, etc.
The wireless communication device may include one or more image sensors, one or more image signal processors, and a memory including instructions or modules for carrying out the local intensity equalization techniques discussed above. The device may also have data, a processor loading instructions and/or data from memory, one or more communication interfaces, one or more input devices, one or more output devices such as a display device and a power source/interface. The wireless communication device may additionally include a transmitter and a receiver. The transmitter and receiver may be jointly referred to as a transceiver. The transceiver may be coupled to one or more antennas for transmitting and/or receiving wireless signals.
Certain aspects of the over current protection devices maybe monitored by a wireless device to provide information relating to the operation of power being transferred from an alternative energy source to one or more of the source lines 4a, 4b. A wireless communication device may wirelessly connect to another electronic device (e.g., base station). A wireless communication device may alternatively be referred to as a mobile device, a mobile station, a subscriber station, a user equipment (UE), a remote station, an access terminal, a mobile terminal, a terminal, a user terminal, a subscriber unit, etc. Examples of wireless communication devices include laptop or desktop computers, cellular phones, smart phones, wireless modems, e-readers, tablet devices, gaming systems, etc. Wireless communication devices may operate in accordance with one or more industry standards such as the 3rd Generation Partnership Project (3GPP). Thus, the general term “wireless communication device” may include wireless communication devices described with varying nomenclatures according to industry standards (e.g., access terminal, user equipment (UE), remote terminal, etc.).
The functions described herein may be stored as one or more instructions on a processor-readable or computer-readable medium. The term “computer-readable medium” refers to any available medium that can be accessed by a computer or processor. By way of example, and not limitation, such a medium may comprise RAM, ROM, EEPROM, flash memory, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray® disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. It should be noted that a computer-readable medium may be tangible and non-transitory. The term “computer-program product” refers to a computing device or processor in combination with code or instructions (e.g., a “program”) that may be executed, processed or computed by the computing device or processor. As used herein, the term “code” may refer to software, instructions, code or data that is/are executable by a computing device or processor.
Software or instructions may also be transmitted over a transmission medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of transmission medium.
The methods disclosed herein comprise one or more steps or actions for achieving the described method. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is required for proper operation of the method that is being described, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.
It should be noted that the terms “couple,” “coupling,” “coupled” or other variations of the word couple as used herein may indicate either an indirect connection or a direct connection. For example, if a first component is “coupled” to a second component, the first component may be either indirectly connected to the second component or directly connected to the second component. As used herein, the term “plurality” denotes two or more. For example, a plurality of components indicates two or more components.
The term “determining” encompasses a wide variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining and the like. Also, “determining” can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory) and the like. Also, “determining” can include resolving, selecting, choosing, establishing and the like.
The phrase “based on” does not mean “based only on,” unless expressly specified otherwise. In other words, the phrase “based on” describes both “based only on” and “based at least on.”
In the foregoing description, specific details are given to provide a thorough understanding of the examples. However, it will be understood by one of ordinary skill in the art that the examples may be practiced without these specific details. For example, electrical components/devices may be shown in block diagrams in order not to obscure the examples in unnecessary detail. In other instances, such components, other structures and techniques may be shown in detail to further explain the examples.
Headings are included herein for reference and to aid in locating various sections. These headings are not intended to limit the scope of the concepts described with respect thereto. Such concepts may have applicability throughout the entire specification.
It is also noted that the examples may be described as a process, which is depicted as a flowchart, a flow diagram, a finite state diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel, or concurrently, and the process can be repeated. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a software function, its termination corresponds to a return of the function to the calling function or the main function.
The previous description of the disclosed implementations is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these implementations will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the implementations shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A device for electrically coupling two power source lines in a circuit breaker panel to an alternative power source, the source lines connected to a main circuit breaker in the circuit breaker panel and each providing power to the circuit breaker panel, to provide an electrical connection between the alternative power source and the power source lines that does not use busbars of the circuit breaker panel for the electrical connection, the device comprising:
- means for electrically coupling including a first means for electrically coupling to a first source line configured to carry 120VAC phase A and a second means for electrically coupling to a second source line configured to carry 120VAC phase B power with two electrically distinct connections, the means for electrically coupling configured to be placed at least partially around the first and second source lines without cutting or disconnecting the first and second source lines, the means for electrically coupling configured to couple to the first and second source line at a location adjacent to the main circuit breaker in a circuit breaker panel and before the first and second source lines connect to the main circuit breaker;
- terminals for connecting to an alternative power source, the terminals including at least a first terminal and a second terminal; and
- means for protecting for an over-current condition electrically connected between the terminals and the means for electrically coupling.
2. The device of claim 1, wherein the means for electrically coupling comprises:
- a threaded slot connector having a slot that allows one of the source lines to pass through the slot and be disposed within the interior of the threaded slot connector, the threaded slot connector having external threads and having at least one tapping spike disposed in the interior of the threaded slot collector; and
- a slotted nut having a slot that allows one of the source lines to pass through the slot and be disposed within the interior to the slotted nut, the slotted nut fitting onto the exterior threads of the threaded slot connector, the slotted nut and the threaded clot connector collectively configured to move the at last one tapping spike to electrically couple to a source line within the threaded slot connector when the slotted nut is wound onto the threaded slot connector.
3. The device of claim 2, wherein the threaded slot connector comprises a tapered shape that deforms when the slotted nut is wound onto the exterior threads to push the at least one tapping spike into the source line.
4. The device of claim 3, wherein the means for protecting for an over-current condition comprises at least one fuse.
5. The device of claim 3, wherein the means for protecting for an over-current condition comprises at least one circuit breaker that is not directly electrically connected to a busbar of the circuit breaker panel.
6. The device of claim 1, wherein the means for coupling include two sets of one or more tapping spikes, each set of the one or more tapping spikes for electrically connecting to one of the first and second source lines.
7. The device of claim 1, wherein the means for electrically coupling comprises two sets of one or more tapping spikes, each set of the one or more tapping spikes arranged to at least partially surround one of the source lines when the means for coupling is placed on the source lines, configured to deform to move the one or more tapping spikes to be electrically coupled to the at least partially surrounded source line when the means for coupling is crimped around the source lines.
8. The device of claim 7, wherein the means for protecting for an over-current condition comprises at least one fuse or at least one circuit breaker.
9. The device of claim 1, wherein the means for electrically coupling comprises:
- a source line receptacle configured to at least partially surround a source line passing through the means for electrically coupling, the source line receptacle including at least one tapping spike,
- a clamping structure disposed along a lower portion of the source line receptacle to secure a source line in the source line receptacle; and
- at least one connector coupled to the clamping structure and disposed to be actuated from an upper surface of the device, the connector extending from the upper surface of the device to the clamping structure, the connector and clamping structure collectively configured to move the clamping structure to a closed position to secure a source line into the source line receptacle and electrically coupling the at least one tapping spike to the source line when the clamping structure is moved to the closed position.
10. The device of claim 1, wherein
- the first means for electrically coupling comprises: a first source line receptacle configured to at least partially surround the first source line when the device is disposed over the first source line so that the first source line passes through the means for electrically coupling, the first source line receptacle including at least one tapping spike, a first clamping structure disposed along a lower portion of the first source line receptacle to secure a source line in the first source line receptacle; and at least one first connector coupled to the first clamping structure and disposed to be actuated from an upper surface of the device, the at least one first connector extending from the upper surface of the device to the first clamping structure, the at least one first connector and the first clamping structure collectively configured to move the first clamping structure to a closed position to secure the first source line into the first source line receptacle electrically coupling the at least one tapping spike to the first source line when the first clamping structure is moved to the closed position; and
- the second means for electrically coupling comprises: a second source line receptacle configured to at least partially surround the second source line when the device is disposed over the second source line so that the second source line passes through the means for electrically coupling, the second source line receptacle including at least one tapping spike, a second clamping structure disposed along a lower portion of the second source line receptacle to secure a source line in the second source line receptacle, and at least one second connector coupled to the second clamping structure and disposed to be actuated from an upper surface of the device, the at least one second connector extending from the upper surface of the device to the second clamping structure, the at least one second connector and the second clamping structure collectively configured to move the second clamping structure to a closed position to secure the second source line into the second source line receptacle electrically coupling the at least one tapping spike to the second source line when the second clamping structure is moved to the closed position.
11. The device of claim 10, wherein the means for protecting for an over-current condition comprises at least one fuse or at least one circuit breaker.
12. The device of claim 1, further comprising a power transfer bar electrically coupled to the means for electrically coupling and extending generally perpendicular to the first and second source lines to fit adjacent to one of more circuit breakers disposed beside the main circuit breaker, the power transfer bar including
- a first conductive bus electrically coupled to the first means for electrically coupling and to the first terminal, and
- a second conductive bus coupled to the second means for electrically coupling and the second terminal.
13. A device for electrically coupling a first source line carrying 120VAC phase A power and a second source line carrying 120VAC phase B power to an alternative power source to feed power from the alternative power source to the first and second source lines without using busbars of a circuit breaker panel, the first and second source lines providing power to a main circuit breaker in a circuit breaker panel, the device comprising:
- a source line coupler configured to couple to the first source line and the second source line in a circuit breaker panel at least partially around the first and second source lines without cutting or disconnecting the first and second source lines, the source line coupler including a first source line receptacle for receiving the first source line when the device is placed over the first source line such that the first source line is disposed in the first line receptacle, the first source line receptacle including at least one first conductive tapping spike disposed to contact the first source line when the first source line is secured in the first source line receptacle; a second source line receptacle for receiving the second source line when the device is placed over the second source line such that second source line is disposed in the second line receptacle, the second source line receptacle including at least one second conductive tapping spike disposed to contact the second source line when the second source line is secured in the second source line receptacle;
- terminals for connecting to an alternative power source, the terminals including at least a first terminal and a second terminal; and
- a first over-current protector and a second over-current protector that stop current from flowing at a predetermined threshold level, the first over-current protector electrically connected between at least one first tapping spike and the first terminal, and the second over-current protector electrically coupled between the at least one second tapping spike and the second terminal.
14. The device of claim 13, wherein the first and second over-current protectors are fuses.
15. The device of claim 13, wherein the first and second over-current protectors are circuit breakers.
16. The device of claim 14, further comprising a power transfer bar electrically coupled to the source line coupler and extending generally perpendicular to first and second source lines that are secured in the source line coupler, the power transfer bar configured to fit adjacent to one of more circuit breakers disposed beside the main circuit breaker, the power transfer bar including
- a first conductive bus electrically coupled between the at least one first tapping spike and the first terminal, and
- a second conductive bus electrically coupled between the at least one second tapping spike and the second terminal.
17. The device of claim 16, wherein the source line coupler comprises;
- a first clamping structure disposed along a portion of the first source line receptacle to secure the first source line in the first source line receptacle; and
- at least one connector coupled to the first clamping structure and disposed to be actuated from an upper surface of the device, the connector extending from the upper surface of the device to the first clamping structure, the connector and first clamping structure collectively configured to move the clamping structure to a closed position to secure the first source line into the first source line receptacle and electrically couple the at least one first tapping spike to the first source line when the first clamping structure is moved to the closed position.
18. The device of claim 17, wherein the first clamping structure is coupled to two connectors disposed to be actuated from the upper surface of the device, the two connectors extending from the upper surface of the device to the first clamping structure and coupled to the first clamping structure.
19. The device of claim 18, wherein the first clamping structure is configured to be adjusted using one or more of the two connectors coupled to the first clamping structure to change the size of the first source line receptacle.
20. A method for installing a device to back feed energy from an energy source to source lines in a preexisting circuit breaker panel, the method comprising:
- inserting a back feed device in a circuit breaker panel between a main circuit breaker and a utility meter, the back feed device dimensioned to couple to a first source line and a second source line and be disposed within the circuit breaker panel, the back feed device comprising: a source line coupler configured to couple to the first source line and the second source line and at least partially around the first and second source lines, the source line coupler including a first source line receptacle for receiving the first source line such that the first source line is disposed in the first line receptacle, the first source line receptacle including at least one first conductive tapping spike disposed to contact the first source line when the first source line is secured in the first source line receptacle; a second source line receptacle for receiving the second source line, the second source line receptacle including at least one second conductive tapping spike disposed to contact the second source line when the second source line is secured in the second source line receptacle; terminals for connecting to an alternative power source, the terminals including at least a first terminal and a second terminal; and a first over-current protector and a second over-current protector that stop current from flowing at a predetermined threshold level, the first over-current protector electrically connected between the at least one first tapping spike and the first terminal, and the second over-current protector electrically coupled between the at least one second tapping spike and the second terminal; and coupling the source line coupler to the first source line and the second source line.
Type: Application
Filed: Dec 30, 2015
Publication Date: Jul 21, 2016
Inventor: Paul Martin Cruz (San Diego, CA)
Application Number: 14/984,933
