An interview with Nick Korth, product marketing manager of energies, HellermannTyton

HellermannTyton manufactures cable management products and identification systems for a number of industries, including solar and wind. The company’s engineered solutions are designed and constructed to meet the strictest quality standards and last in the harshest conditions — from desert solar environments to salt-sprayed offshore wind farms. HellermannTyton formed in 1969 in Wisconsin and today operates in 39 countries. We talked with Nick Korth, product marketing manager of energies, to get some insight into how cable management is evolving on solar projects.

Wire management is critical on all solar projects. Whether residential, commercial or utility-scale, protecting the wires is critical to long operating life. A lack of wire management, or wire management strategy for that matter, including misapplication or poor product design, can lead to long-term issues, including fires.

There is no one rule of thumb when it comes to wire management. Safety of the wires is the No. 1 priority, and there are many ways for an installer to achieve this goal. At HellermannTyton, we have written several white papers and best-practice guides, presented webinars to foster these standards, and SEIA is working on best practices as part of their committee work. With that said, best practices are only suggestions, and within the framework of the NEC, there is little that “polices” the actual routing and protection of the cabling.

One example of this is the new addition to the National Electric Code, 690.31(C)(1): “Exposed cables shall be supported and secured at intervals not to exceed 600 mm (24 in.) by cable ties, straps, hangers or similar fittings listed and identified for securement and support in outdoor locations.” While this reference is providing a guideline on where to place wire management, it will not instruct installers how to install the product. It will have significant impact on the industry moving forward, because in places like the back of a solar module or frameless modules, there are no wire management attachment points.

That is where HellermannTyton likes to educate our customers, take a hands-on approach when golden rows are being installed, and be a true solutions provider instead of a part manufacturer. Each utility-scale project is unique, be it the module or racking or BOS design, so consulting with our customers can help prevent issues during installation and save on maintenance costs down the road.

This is a conversation we have with every one of our customers. Many considerations go into selecting the right material for wire management. How confident are you that the product will be installed correctly? What environmental factors will affect the installation? What type of racking and modules are being used?

As one of the world’s largest manufacturers of cable ties and having nearly 70,000 different parts, we have a solution for virtually any situation. Plastic materials provide safety that metal can’t, but they have lower potential longevity. There are many different grades of plastic available today — Acetal, Nylon 6, Nylon 12, PVDF — and many different modifiers that can alter the characteristics of those base materials. These modifiers can help plastics survive better in direct sunlight or keep moisture levels stable to avoid brittleness.

And yet, developers and installers have incurred exorbitant costs because an inferior plastic was specified or inappropriately installed, and the wire management must be completely replaced. One truck roll on a residential installation can eliminate much of the profit and having to replace 100,000 cable ties represents a lot of labor expense, all for a part that can cost as little as a penny. So, they specify metal. Metal and coated metal products provide the assurance that the product will last 25 years in most circumstances, but metal can easily damage cable jackets and a ground fault can lead to more serious issues. Coated metal parts create a “false security” of long life, but the plastic that insulates the metal from the wires is subject to metal-to-conductor failures.

Consequently, both metal and plastic have their benefits and flaws. By having a good design plan in choosing the proper material for the application and having a good follow-up O&M plan to observe and monitor, our customers have been happy choosing plastic wire management solutions.

Modules are difficult to design wire management around. Every module is a little different, be it the module mounting hole, the edge thickness of the frame or even the frame design. HellermannTyton has a variety of solutions for module level wire management to address these differences.

That is not always the case with utility-scale projects. As the utility-scale market transitions to less material, it also creates fewer routing options. Punched holes are cost prohibitive or impede structural integrity, and certain metal profiles are difficult to attach to. With the new changes to NEC 2020 and 690.31(C)(1), it will be even more of a challenge. Routing wires along the torque tube will become more prominent. One reason is the lack of edges and holes to mount wire management. Another is split junction boxes that are often located close to the center of the module. Often a MIB or support bracket for the module on a single-axis tracker interferes with typical wire management placement and creates difficulty attaching to modules. And with bifacial projects, developers want to squeeze every watt of power out of their projects, and shading of the back of the modules tends to be avoided. This brings new challenges because racking manufacturers do not typically allow for holes or anything being attached to the torque tube. Heat and movement are serious environmental concerns along the torque tube. With metal pieces that large, they can move throughout the day as the array thermocycles and can often get as hot as 160°F.

We are seeing a trend of new products (racking and modules) whose designers seem to have forgotten that wire management even happens. There must be an attachment point for wire management, and designers of new module frames and racking structures are not considering the available range of parts in their designs. This realization often doesn’t happen until structures are being erected and modules attached — a bad time to realize there are few options currently available.

Joe, thanks for the comment and definitely a common application! One thing to be careful of, rodents (squirrels) love to burrow up in winter in those wires because they are warm! One thing to keep in mind

Nice to be aware of 690.31(C)1. I’ve always been a fanatic about wire dress, but now it’s mandatory! I personally love racking that has an open, upwards facing C or U channel – and I tuck my wires in the channel, safely out of the way of critters and chafing!

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