This invention generally relates to the mounting of framed photovoltaic (PV) modules atop roofs and other support structures, where positive mechanical securement of the modules to the supporting base or structure is desirable and electrical grounding of accessible metal components, such as the PV module frame and ancillary mounting components, is required. Known combined mounting/bonding devices require a special flange on the outside of the photovoltaic module frame and a specially designed clip or other attachment device. Therefore, conventional combined mounting/bonding devices are limited to use with specific module frame geometries.
A mounting/bonding clip for use with first and second photovoltaic (PV) modules of the type including an electrically conductive frame and separated by a gap, the clip comprising an electrically conductive body comprising a central portion and first and second spaced-apart arms extending from the central portion, each arm extending from the central portion at an obtuse angle to the central portion. Each arm has first and second outer ends with frame surface-penetrating or surface-disrupting electrical contact element at each outer end. The frame surface-penetrating element points generally towards the plane of the central portion. The frame surface-penetrating element of each arm is orientable in a direction generally perpendicular to the PV module frame. The frame surface-disrupting element may comprise surface-penetrating teeth. The body of the clip is generally U-shaped.
The first and second spaced-apart arms extend from the central portion at an obtuse angle to the central portion. This aspect of the design of the clip provides a wider and more stable mounting application to electrically bond photovoltaic module frames to each other and to a grounded mounting structure, versus prior art clips comprising first and second spaced-apart arms, each extending from the central portion at an acute or right angle to the central portion. As the clip is tightened onto PV module frames, the clip makes contact with the frame and the first and second spaced-apart arms drag inwards, making significantly better bonding contact versus prior art clips.
An example of an electrically conductive mounting/bonding clip assembly, for use with an array of PV modules of the type having electrically conductive frames separated by gaps, includes an electrically conductive clip and a second member. The clip includes a central portion and first and second spaced-apart arms extending from the central portion at an obtuse angle to the central portion. Each arm has first and second outer ends. A frame surface-disrupting element is at each outer end. The central portion defines a plane and the frame surface-disrupting elements point towards the plane. The clip assembly also includes means for (1) biasing the frame surface-disrupting elements of the clip against electrically conductive frames of adjacent PV modules thereby electrically connecting the frames to one another through the clip, and (2) securing the clip to the second member.
An example of a PV installation includes a support, first and second PV modules and an electrically conductive mounting/bonding clip assembly for use with the first and second PV modules. The first and second PV modules are of the type having electrically conductive frames separated by a gap, the frames each having an upper surface. The clip assembly comprises an electrically conductive clip. The clip includes a central portion and first and second spaced-apart, generally T-shaped arms extending from the central portion at an obtuse angle to the central portion. The central portion and arms define an access region accessible from above. Each arm has first and second outer ends. At least one frame surface-disrupting element is at each outer end. The central portion defines a plane. The frame surface-disrupting element points towards the plane. The clip assembly also includes a second member, positioned generally beneath the first and second PV modules and supported by the support, and an elongated connection member. The elongated connection member secures the clip to the second member and is extendable within the gap between the electrically conductive frames so that the frame-disrupting element can be forced against the electrically conductive frames thereby electrically connecting the frames to one another and simultaneously mounting the PV modules to the support through the clip. The central portion includes a hole and the elongated connection member comprises a connection element passing through the hole. The connection element has an upper end located completely within the access region and below the upper surface of the clip. In some examples the frame comprises an electrically non-conductive surface and the frame surface-disrupting portion comprises surface-penetrating teeth. In some examples the connection element may include a threaded member, such as a bolt or a stud.
The features, functions, and advantages may be achieved independently in various embodiments of the disclosure or may be combined in yet other embodiments.
Embodiments of the disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
Referring to
The racking beam 18 may include a base 20, typically of extruded aluminum or some other appropriate material. The racking beam 18 may have a “U” shape frame having a pair of channels 22, with each channel positioned in the top section of each leg of the “U” shape frame.
The channel nut 14 may have a pair of notches 24 formed thereon. In one embodiment, the pair of notches 24 are formed on opposing sides of the channel nut 14. The pair of notches 24 may be formed to allow the channel nut 14 to be positioned within the “U” shape frame of the racking beam 18 by sliding the pair of notches 24 of the channel nut 14 within the pair of channels 22 of the “U” shape frame of the racking beam 18.
Once the channel nut 14 is positioned within the “U” shape frame of the racking beam 18, a securing device in the form of elongated connection member 16 may be used to secure the clip 12 to the racking beam 18. In one embodiment, a bolt 16A may be used. The bolt 16A passes through a central opening 26 in clip 12 and through a hole 28 formed in the channel nut 14. In one embodiment, the central opening 26 in clip 12 may take the shape of a circular hole. The hole 28 may be a threaded hole to secure the bolt 16A to the channel nut 14. A lock washer 30 may be positioned between the clip 12 and the bolt 16A. In accordance with one embodiment, the lock washer 30 may be a circular ring. Thus, the bolt 16A may pass through the lock washer 30, the central opening 26 in clip 12 and through the hole 28 formed in the channel nut 14.
The first and second spaced-apart arms extend from the central portion at an obtuse angle to the central portion. This aspect of the design of the clip 12 provides a wider and more stable mounting application to electrically bond photovoltaic module frames 10 to each other and to a grounded mounting structure, versus prior art clips comprising first and second spaced-apart arms, each extending from the central portion at an acute or right angle to the central portion. As the clip 12 is tightened onto the photovoltaic module frame 10, the clip 12 makes contact with the frame 10 and the first and second spaced-apart arms drag inwards, making significantly better bonding contact versus prior art clips.
Referring now to
A support structure 36 used to mount the photovoltaic modules 10 must include a hole 38. The support structure 36 may take the form of a C-, Z-, or L-shaped purlin, typically of steel or some other appropriate material.
The bolt 16A′ passes through a central opening 26 in clip 12, through hole 38 in support structure 36 and finally through a hole 34 formed in the hex nut 32. In one embodiment, the central opening 26 in clip 12 may take the shape of a square hole. The hole 34 may be a threaded hole to secure the bolt 16A′ to the hex nut 32. A lock washer 30′ may be positioned between the hole 38 in support structure 36 and the hex nut 32. In accordance with one embodiment, the lock washer 30′ may be a circular ring. Thus, the bolt 16A′ may pass through the central opening 26 in clip 12, the hole 38 in the support structure 36, the lock washer 30′ and finally through the hole 34 formed in the hex nut 32.
The first and second spaced-apart arms extend from the central portion at an obtuse angle to the central portion. This aspect of the design of the clip 12 provides a wider and more stable mounting application to electrically bond photovoltaic module frames 10 to each other and to a grounded mounting structure, versus prior art clips comprising first and second spaced-apart arms, each extending from the central portion at an acute or right angle to the central portion. As the clip 12 is tightened onto the photovoltaic module frame 10, the clip 12 makes contact with the frame 10 and the first and second spaced-apart arms drag inwards, making significantly better bonding contact versus prior art clips.
Referring now to
In the embodiment shown in
Arms 42 are preferably not perpendicular to central portion 40. In the disclosed example, arms 42 extend outwardly over central portion 40 to define an included angle 47. Included angle 47 is an obtuse angle. In the embodiment shown in
Due to the vertical contact with the photovoltaic module frames 10, a downward application of force from the positively attached bolt 16A/16A′ on the central portion 40 of the clip 12 results in horizontal motion of the arms 42 and outer ends 44 in the direction of the central portion 40. This translational motion is resisted by the module frame 10 whereby the friction between the clip 12 and frame 10 results in the teeth 46 gouging the anodized non-conductive surface of the frame 10, thus exposing the conductive material beneath. This result is best achieved when included angle 47 is an obtuse angle.
In operation, as shown in
Referring to
While embodiments of the disclosure have been described in terms of various specific embodiments, those skilled in the art will recognize that the embodiments of the disclosure may be practiced with modifications within the spirit and scope of the claims.
This application is related to U.S. Pat. No. 7,780,472, issued on Aug. 24, 2010 and is hereby incorporated herewith.