Page 17 - North American Clean Energy May June 2018 Issue

solar power
Wire management gone bad. An unidentified supplier’s UV rated cable ties, passed through a module hole, failed and significant rework was needed.
Avoid Wire Management Disasters in Three Easy Steps
Here’s where UV stabilized fasteners truly shine. Designed with a mounting base or a cable tie buckle, these products will last ve to seven times longer than a UV rated cable
tie through a module mounting hole. Parts made from UV stabilized plastic, along with other modi ers, can drastically increase the life expectancy of these products in the elements.
In fact, some plastic compounds
can last even longer, around 15 to 25 years. Choosing engineered plastics designed to perform in the elements will consistently deliver rewards.
C
Lastly, come up with a sound O&M strategy. Consider the combiner box M
shown above. e wire entry was sealed with a compound, but one
that was not rated for outdoor use.
As the compound aked away, water seeped into the conduit and owed CY down to the combiner box. A more CMY routine maintenance schedule could K have caught this issue before leading to expensive xes. Unfortunately, in this case, a complete combiner box replacement was required.
Focus on these three steps to successfully master solar installation costs and risks. E ective wire management can help save money at installation, reduce installation times and maintenance visits, and continue delivering over the long term.
Nick Korth is the Product
Marketing Manager – Energies at HellermannTyton North America.
e manufacturer provides solar solutions that connect, fasten, route, protect, and identify. HellermannTyton demonstrates an ongoing commitment to industry education and safety.
H|ellermannTyton www.hellermanntyton.us
>400MWs of energy storage inverters, DC converters and energy storage systems installed worldwide.
by Nick Korth
INCREASE pROJECT REVENUES
Just like the weather, poor wire management application
and lack of strategy can be catastrophic. Unlike storms and natural disasters, however, wire management failure on solar installations is not only predictable, but also easily preventable.
If you want to reduce risk and added costs, consider the following three-step process:
e rst step is education. NEC 2017 prescribes a number of requirements dictating proper wire management – unfortunately, they tend to be open to interpretation.
According to NEC 110.12, “Electrical equipment shall be installed in a neat and workmanlike manner.” NEC 338.24 refers to “insu cient support of conductors and stress on junction box and plug connections.”
ese codes provide a baseline for evaluation and inspection, but they don’t guarantee a long-lasting installation. Seeking out best practices, and adopting quality assurance programs, will go a long way to ensure that installers learn and practice proven installation procedures.
For example, one site actually had a plastic-coated metal cable tie routed through a module hole. e tie was so tight that, due to wind and thermos- cycling, it had sliced through the wire jacket and caused a fault. is is
a pro t killer; any time you have to repair a serious fault, you drastically reduce your pro t margins.
Another example was damage to a cable jacket because of poor application of metal clips. It’s not uncommon to see workers pounding on poorly designed, cheap metal clips, with the back of a side cutter or screwdriver. Not only does this distort the actual clip, which a ects performance, it can cause damage to the module itself. e solution is to use better metal clips that are designed to go on easily, and hold incredibly well.
e second step in having a good wire management plan is specifying the correct materials, and having the correct product for the application. Plastic products often get a bad reputation in the solar industry, and are frequently seen as a poor alternative to metal. But, like all products, quality is often relative; you get what you pay for. Not all plastic wire management products are created equal. Plastic cable ties get a bad rap. Like everything else on the market, there are varying levels of quality; don’t let the reputation of inferior plastic products scare you away from seeking out and using a stronger, well-made, and lasting plastic cable tie.
One particular site happened to be in a desert environment, but had cheap, “UV rated” cable ties looped through solar module mounting holes. After three replacements in four years, the owner of this single axis tracker installation decided enough was enough; he speci ed and was able to nd a product to match the hazards of constant heat, thermo-cycling, wind, and sun.
But think about this: four laborers for ve days, at $20 per hour, adds up to $3,200 a year. Over the course of ve years, a site owner could spend $16,000 on labor for replacing cheap cable ties alone, signi cantly adding to the operations costs. at’s in addition to the multiple faults and connector failures, and the added risk of junction box failure due to strain on the lead wires.
DC-coupled solar plus storage
Solar wire management products
Advanced Cable Ties, Inc.’s NYLON 12 Cable Ties are molecularly designed to withstand the harsh rays of the sun and corrosive outdoor elements. e unique properties of Nylon 12 make it a solution for engineers designing for solar and wind power applications as well as other extreme climate environments. Nylon 12 Cable Ties resist temperature uctuations, are chemical resistant, and insensitive to stress cracking. e smooth edges eliminate abrasion damage and won't cut into panel cables. Low water absorption and high density maintains the stability of the cable tie providing ultra-long lasting performance for solar panel systems. Advanced Cable Ties produces a complete range of sizes from 5" up to a 14" heavy duty in convenient contractor packaging of 100 per bag and 1,000 per case, made in their Gardner, MA facility.
Advanced Cable Ties, Inc. | www.advancedcableties.com
Y CM MY
Adding energy storage to a new or existing utility-scale -solar installation with a Dynapower DC-DC converter can increase PV energy production through clipping recapture and low voltage harvest. Further adding to your bottom line, DC-coupled solar plus storage has a higher efficiency -than AC-coupled storage and is eligible for valuable tax incentives for installation owners.
To learn more about how Dynapower’s patent-pending line of DC-DC converters can increase project revenues and lower the installation costs of utility-scale solar plus storage, please visit our website to download the
white paper.
To speak with a sales engineer today about modeling your project for energy storage, please call
NACE.001.18_SOLAR_DCAD.pdf
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Clipped PV Production kWh/Month
32 MAY•JUNE2018 /// www.nacleanenergy.com
1.877.215.0487
SAMPLE 20MW PV INSTALLATION W I T H O U T D C - C O U P L E D S T O R A G E
Annual Lost Production:
275,000 225,000 175,000 125,000 75,000 25,000
249,548
231,174 231,046
176,789
121,861
203,916 183,129
90,625
JAN FEB MAR APR MAY
83,252
73,047
WWW.DYNAPOWER.COM/DC-DC
250kW to 3MW
North American Clean Energy 33
JUN JUL
AUG SEPT
OCT NOV DEC
1 , 9 2 3 k , W2 h5 6 k W s
160,919 117,948
Inverter Loading Ratio = 1.45