{"id":13108,"date":"2017-07-18T17:34:37","date_gmt":"2017-07-18T07:04:37","guid":{"rendered":"https:\/\/www.solarquotes.com.au\/blog\/?p=13108"},"modified":"2020-12-30T14:41:12","modified_gmt":"2020-12-30T04:11:12","slug":"solar-panel-clamping-zones","status":"publish","type":"post","link":"https:\/\/www.solarquotes.com.au\/blog\/solar-panel-clamping-zones\/","title":{"rendered":"Solar Panel Clamping Zones: Are Your Panels Mounted Correctly?"},"content":{"rendered":"
\"clamping

That clamp is not in the zone! After reading this post you will know what that means. (Photo credit:<\/strong> Matt Hines<\/a> – definitely not one of his installs)<\/em><\/p><\/div>\n

There is one main way solar panels are attached to roofs in Australia and I’m hoping you won’t be surprised to learn it’s not glue.\u00a0 If you’ve got panels, they are almost certainly fastened to your roof with clamps and held tight in the loving embrace of metal brackets.<\/p>\n

When solar is installed on a typical roof, whether it is tin or tile, rails, also known as racks, are securely fastened to roof rafters.\u00a0 Panels are laid on top of these rails and held firmly in place with clamps.\u00a0 While there are other ways of attaching solar panels, including directly bolting them on, clamps are by far the most common method.\u00a0 Convenience is the main reason, but it is effective and I expect the large majority of correctly clamped panels will still be in place 40 years from now.<\/p>\n

Properly clamping panels so they meet the manufacturer’s instructions (and therefore the Australian Standards for installation) involves using the right number of clamps in the right places.\u00a0 The areas on a panel where clamps can be clenched are known as zones and panels can have more than one type.\u00a0 If you are interested in learning about clamping zones, what you should check to see if your panels are properly clamped, and what you can do if they’re not, then please read on.<\/p>\n

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I stole this image from Sunlock<\/a>, a maker of roof mounting systems. The great thing about clamps is, if you use an Allen key to tighten that bolt, you don’t have to stand there and hold them in place like in this picture. Also, you probably wouldn’t need that extra bit of railing sticking out to rest your hand on.<\/p><\/div>\n

Bolts On Roofs Is Nuts<\/h2>\n
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Sunlock<\/a> clamps: The top one is an end clamp used when there is no adjacent panel and the other is a mid or inter clamp that goes between panels.<\/p><\/div>\n

Solar panels can be directly bolted into place and panels will generally come with either four or eight mounting holes for bolts to be placed through.\u00a0\u00a0 This method is often used in solar farms to attach panels to ground mounted racks or to solar trackers that follow the sun through the day.\u00a0 It is possible to use bolts because on a ground mount or a tracker there is plenty of room to get behind the panels and attach them.\u00a0 But on a roof where panels are laid flat this is not at all easy.<\/p>\n

Australian standards require a gap of at least 5 cm between roofs and solar panels.\u00a0 However, in urban areas, panels are generally not allowed to extend more than 10 cm from the surface.\u00a0 As a typical solar panel is around 4 cm thick, this only leaves a 5 to 6 cm space in which to work.\u00a0 So directly bolting panels on would require either fancy tools or magic hands to get the job done.<\/p>\n

Clamps Rule and Clamp Rules<\/h2>\n

Because bolts are so bothersome, by far the most common method for permanently perching solar panels upon people’s household canopies of tin or tile is for them to be firmly clenched in the clasp of clamps.<\/p>\n

Clenched clamps are clearly the most common category of connector chosen when it comes to cohering panels to racks and roofs and are capable of doing their duty for decades.<\/p>\n

But in order for clamps to be effective in holding panels in place in all kinds of weather, there are certain rules that must be followed about where they can go.\u00a0 These rules involve clamping zones.<\/p>\n

Clamping Zones<\/h2>\n

Clamping zones can vary from panel to panel.\u00a0 Many panels only have one type of clamping zone, which will be located around its mounting holes.\u00a0 Other panels can have multiple zones which will give an installer options on where to install clamps, depending on what wind conditions are like at a location.<\/p>\n

You can find information on your panels’ clamping zones by searching for the brand’s installation manual or installation guide.<\/p>\n

Clamping Zone Examples<\/h2>\n

This kind of dull-looking diagram is from\u00a0LG Solar’s<\/a> installation instructions<\/a>:<\/p>\n

\"LG<\/p>\n

As you can see, LG’s panels only have one type of clamping zone, which is located around its four sets of two mounting holes.\u00a0 The mounting holes are, quite sensibly, located in the best positions to anchor a panel.<\/p>\n

The more colourful diagram below shows a solar panel with three different clamping zones and is from the Yingli Solar PV Modules Mounting Guide<\/a>.\u00a0 Yingli Solar<\/a> was the world’s largest manufacturer of solar panels and now it’s not.\u00a0 (If you are going to follow the ups and downs of solar panel manufacturing, make popcorn.\u00a0 It’s a real soap opera.)<\/p>\n

\"Clamping<\/p>\n

As you can see there are three clamping zones numbered in order of effectiveness.<\/p>\n

Zone 1 = The best<\/p>\n

Zone 2 = The not so best<\/p>\n

Zone 3 = The least best<\/p><\/blockquote>\n

In addition, in the middle of each side, there is an area that is not part of any clamping zone.<\/p>\n

Zone 1 is centered on each of the four mounting holes and is 10 cm long.<\/p>\n

Zone 2 is the second-best place to clamp a panel.\u00a0 They are located next to zone 1 on the side closest to the center of the panel and are 15 cm long.<\/p>\n

Zone 3 is located around the corners of the panel and is the least secure of all three clamping zones, but it is better than the “no zone” areas in the center of the panel’s edges.<\/p>\n

This table from the Yingli Mounting Manual lays out the effects of applying clamps in different zones on their standard-sized 60 cell panels:<\/p>\n

\"Yingli<\/p>\n

The upward loads under “Maximum Load (Pa)<\/strong>” are caused by the wind trying to blow the panels off the roof, while downward loads are caused by snow piling up on panels — a problem we rarely have in Australia.\u00a0 According to the table, a panel with clamps in each of its 4 zone 1s can withstand 26% more powerful winds than a panel with its four-zone 2s clamped, and 58% more powerful winds than a panel with its zone 3s clamped.<\/p>\n

Clamps Needs To Be Symmetrically Arranged<\/h2>\n

Clamps used to secure solar panels should be positioned symmetrically.\u00a0 To use a technical term, the position of clamps should not make a panel appear “wonky”.\u00a0 Once again, I turn to the Yingli Mounting Manual for assistance:<\/p>\n

\"Clamping<\/p>\n

Help!\u00a0 There Are Clamps In My “No Zone” Areas!<\/h2>\n
\"Ice

An Ice Warrior from Doctor Who proudly displaying his hand clamps. Or possibly a Lego man after it has been exposed to gamma rays.<\/p><\/div>\n

If you look at your panels and see there are clamps located outside of clamping zones, there is no need to panic.<\/p>\n

Not yet, anyway.<\/p>\n

Look at your panel and see if there are four clamps symmetrically arranged in valid clamping zones.\u00a0 If so, then you have nothing to worry about.\u00a0 The clamps in the “no zone” areas are doing no harm and are providing extra anchoring for your panel.<\/p>\n

If there aren’t four clamps properly located in clamping zones, then if you want to panic, feel free to do so for a little while, just to get it out of your system.<\/p>\n

If there are less than four clamps properly placed in clamping zones then any placed in the “no zone” areas will result in stress being placed on weaker parts of the panel. \u00a0 This can cause the panel to flex in the wind, which is bad as it can cause microfractures to form in the solar cells and degrade their performance.\u00a0 Given enough time, or just one really bad storm, it could result in clamps failing and the panel being blown off the roof.<\/p>\n

If your installer hasn’t properly clamped your panels you need to get them to fix the problem as soon as reasonably possible.\u00a0 It doesn’t matter if their workmanship guarantee is over or how much time has passed.\u00a0 In Australia you are protected by consumer guarantees<\/a> that require products be:<\/p>\n