Patent Application
20170170579
Field
The present disclosure relates generally to bonding clamps, and more particularly to bonding clamps used to secure photovoltaic module frames to rail systems while providing an electrical bonding between the frames.
Description of the Related Art
Photovoltaic arrays are typically composed of a number of photovoltaic modules set within a metallic frame, and a rail system that supports the photovoltaic modules. When installing a photovoltaic array, a number of photovoltaic modules are assembled onto a larger mounting structure, sometimes called rails or racking structures. The metallic frames of the individual photovoltaic modules, and the structural pieces, e.g., the rails, on which the modules mount are generally made out of aluminum, which is typically anodized to resist corrosion. Although the frames of the photovoltaic modules are directly bolted or clamped to the rails, the anodizing insulates the metal structures so that they may not be electrically bonded, unless measures are taken to electrically bond them.
Like other sources of electrical power, to ensure safety, the metal frames of the photovoltaic modules and the metal rails on which they are secured are often required by national or local electrical codes to be electrically bonded. Electrically bonded is used here in the technical sense to mean forming an electrically conductive path between the metal structures to ensure electrical continuity between the metal structures sufficient to safely conduct any electrical current imposed on the metal structures.
To electrically bond the metal structures, a common practice in the industry is to install a separate grounding lug on each piece that is anodized, or a separate grounding washer between anodized metal structures. A grounding lug is attached to the sheet metal frame of the photovoltaic modules with a thread forming stainless steel screw. Since the screw cuts into the aluminum it forms a connection which can maintain an electrical bond over time. However, a common sheet metal thickness is fairly thin, e.g., 0.080 inch, and a common screw size is 10-32 so that the screw therefore only makes connection on about 2½ threads, which provides a marginally acceptable surface contact area in terms of mechanical strength and electrical conductivity. Using separate bonding washers between metal structures provides a larger electrical contact area for an improved electrical bonding connection. However, adding grounding lugs or separate bonding washers increases the cost to install photovoltaic arrays, in terms of supplies, and in terms of labor costs to install the separate bonding components.
The present disclosure provides descriptions of embodiments for bonding clamps used to assembly photovoltaic (PV) arrays, and provide an electrical bond between PV module frames forming part of the PV arrays. In one exemplary embodiment, the bonding clamp includes an electrically conductive body having a top side, a bottom side, a fastener receiving member, for example an aperture, for receiving a mounting fastener, and at least one electrical bonding member extending from the bottom surface of the body, a first spacer member extending from the electrically conductive body in a direction away from the bottom surface of the body, and a second spacer member extending from the electrically conductive body in a direction away from the bottom surface of the body. The electrically conductive body can be substantially planar. In another exemplary embodiment, the bonding clamp includes an electrically conductive body having a top side and a bottom side, a first spacer member extending from the electrically conductive body in a direction away from the bottom surface, and a second spacer member extending from the electrically conductive body in a direction away from the bottom surface. The second spacer is aligned with the first spacer member such that the first and second spacers define two portions of the body that include at least one electrical bonding member extending from the bottom surface of the body.
In one exemplary embodiment, the first spacer member extends from one end of the electrically conductive body, and the second spacer member extends from an opposite end of the electrically conductive body. In another exemplary embodiment, the first spacer member extends from the bottom surface of the electrically conductive body, and the second spacer member extends from the bottom surface of the electrically conductive body.
The at least one electrical bonding member may include a plurality of electrical bonding members, wherein each of the plurality of electrical bonding members comprises a single tooth. In some embodiments, the single tooth has a serrated distal end.
The figures depict embodiments for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures illustrated herein may be employed without departing from the principles described herein, wherein:
The present disclosure provides descriptions of embodiments for bonding clamps used to assembly photovoltaic (PV) arrays, and provide an electrical bond between PV module frames forming part of the PV arrays. This specification and the accompanying drawings are to be regarded in an illustrative sense rather than a restrictive sense. Various modifications may be made thereto without departing from the spirit and scope of the present disclosure.
Referring to
Extending from opposite ends of the body 12 are spacer members 18, e.g., spacer arms. The spacer arms 18 provide a substantially uniform spacing between PV modules frames when secured to a rail system, as will be described below, and also ensure that the bonding clamp 10 does not rotate when being secured to the rail system to ensure the electrical bonding. In one embodiment, the spacer arms 18 extend outward from the body 12, and have a bend which is in substantially the same direction as the electrical bonding members 16 extending from the bottom surface 12b of the body 12. The bend in the spacer arms 18 should be sufficient so that the spacer arm 18 falls between PV module frames, as seen in
Referring to
Turning to
To secure the PV module frames 30 to the rail 40, a mounting fastener 42, e.g., a nut and bolt, or rivets can be used. In this exemplary embodiment, a bolt 44 is passed through aperture 14 in the body 12 of the body clamp 10, between the PV module frames 30, and through aperture 48 in rail 40. A nut 46 is then attached to the bolt 44 and tightened to secure the bonding clamp 10 to the PV module frames 30, and the PV module frames 30 to the rail 40. As shown in
While illustrative embodiments of the present disclosure have been described and illustrated above, it should be understood that these are exemplary of the disclosure and are not to be considered as limiting. Additions, deletions, substitutions, and other modifications can be made without departing from the spirit or scope of the present disclosure. Accordingly, the present disclosure is not to be considered as limited by the foregoing description.
The present disclosure is based on and claims benefit from co-pending U.S. Provisional Application Ser. No. 62/264,987 filed Dec. 9, 2015 entitled “Bonding Clamp” the entire contents of which are herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62264987 | Dec 2015 | US |
