Heyco introduces four new cable tie products

Heyco has recently added multiple new products to its already extensive line of Cable Ties including Nylon 12, Blind Mount, Releasable, and HEYBite Cable Ties. Let’s meet the newbies.

Heyco cable ties

Heyco Nylon 12 Cable Ties are weather/UV resistant and suitable for high moisture, corrosive (zinc chloride and dilute acids) and low temperature indoor or outdoor applications. These ties are available in various lengths to accommodate a variety of different bundle sizes ranging from 1.44″ all the way up to 4.00″ bundles and the tensile strengths range from 40lbs all the way up to 100lbs.

Heyco blind mount cable tie

Heyco Blind Mount Cable Ties have a low insertion force with high pull out retention capabilities and can be mounted in either a through hold or a blind hole of proper depth. Due to the blind mount being assembled to the cable tie, no additional components are required.

Heyco releasable cable tie

Heyco Releasable Cable Ties have a locking mechanism that can be released so that wires can be added or removed from the bundle without cutting or otherwise damaging the cable tie.


The HEYBite Clip mounts easily to frames and panel edges without the need for mounting holes or adhesives. The metal locking teeth bite easily into frames and panel edges, yet provide high removal resistance. HEYBites’ two piece assembly easily adjusts to various bundle diameters.

— Solar Builder magazine

New Solar-Log monitoring gateway aimed at price-sensitive PV projects 15-kW and under


The all new Solar-Log 50 Gateway, a compact, advanced residential solar monitoring solution, is now available in the U.S.  Officially launched in Germany in December 2017, the Solar-Log 50 is ideal for the price-sensitive residential solar market segment, for plants up to 15 kW. Its modular hardware and software pricing means users only pay for the features they need.

“The solar monitoring landscape is changing. Policy changes can lead to uncertainty, meaning that having a cost-effective option for the price-sensitive residential market is important now more than ever,” says Anthony Conklin, President of Solar Data Systems, Inc. (Solar-Log). “The newest generation of Solar-Log offers a modular pricing structure to help keep O&M costs down, without sacrificing the reliable Solar-Log data that the industry depends on.”

How’s it work?

This gateway is designed to be used in combination with the Solar-Log WEB Enerest portal and provides reliable PV yield and plant performance data through inverter direct communication. The Solar-Log aggregates data from over 100 inverter brands through RS485 or Ethernet connection. Data is transferred via wired internet connection (required) and visualized on the Solar-Log WEB Enerest portal. The compact, din rail mountable hardware can be installed in as little as 10 minutes.

Keep Watch: How the PV monitoring landscape is evolving

The included Solar-Log WEB Enerest M monitoring subscription is a simplified solution for homeowners who want to monitor their plants themselves. The monitoring subscription can be upgraded, for a subscription fee, to the L or XL package at any time, for installers offering O&M service contracts to their customers. The Solar-Log WEB Enerest processes the recorded data, making numerous reports possible, and has analysis tools for the efficient use of solar energy. The user is continuously informed about plant performance and potential malfunctions.

Numerous add-on functions for the Solar-Log 50 Gateway are available through corresponding licenses. Add-ons include feed-in management, increased plant size compatibility, and integration of additional components. The Solar-Log 50 will be available through a wide variety of distributors and installers across the nation.

— Solar Builder magazine

DC decisions: Large-scale PV wiring trends are leaving behind DC combiners, cables

inverter pad

Closer to the grid connection, interrupt ratings are higher, which is why SolarBOS recommends fuses instead of breakers.

All large-scale PV projects will involve a ton of modules and only one grid connection, so all of the aggregation decisions made in between comprise a big chunk of a profitable project pitch. We asked two major eBOS suppliers for the trends leading the way in large-scale PV wiring in 2018, and both of them point to huge reductions in traditional DC wiring and an emphasis on fuses.

Goodbye DC combiners

The most significant DC wiring trend for Jason Whitaker, president of Shoals, has been the migration away from the traditional combiner paradigm to harness assemblies, which is a big step toward simplification and reducing the amount of DC cable needed. The Big Lead Assembly (BLA) is a prime example.

“What previously had been the feeder cable, running from the inverter to the combiner, has now become the entire solution in itself: The BLA, a large conductor, tailored for each site, in which all the PV circuits are combined as they branch off from the BLA at the optimal electro-mechanical positions within the array,” he says. “This allows for a streamlined, plug-and-play installation.”

Pre-paralleling PV strings and incorporating in-line fuses can further reduce the amount of cabling needed.

“If the ILF [in-line fuse] saves more than 25 ft of PV cable, it has paid for itself,” Whitaker says. “ILFs can significantly reduce both the amount of cable required within a PV array and the number and/or size of combiners deployed.”

On a typical tracker installation with combiners and component harnesses (ILFs), a 39 percent reduction in DC string wiring can be expected. Then, factor in the BLA, and that number moves to about a 51 percent reduction. Note: Shoals also recently partnered with Array Technologies on a solution tailored to its tracker system, which improves those economics even more.

“Optimization of the electrical and mechanical systems together will result in a decreased installation time while simultaneously increasing system reliability,” Whitaker says.

All that, coupled with significant labor savings will result in the lowest installed cost solution. The BLA not only provides value from a CAPEX perspective, it also offers significant savings in OPEX when you consider the increased reliability and the elimination of components that require operations and maintenance (O&M).

Shoals’ Big Lead Assembly

Diagram of the streamlined design of Shoals’ Big Lead Assembly combined with in-line fuses.

Hello AC combiners

The philosophical shift in the industry from central inverters to string inverters in larger-scale applications has big implications for eBOS decisions. What was typically all DC aggregation is a big mix of DC and AC. Coel Schumacher, CTO of SolarBOS, sees this as a chance to install fused AC combiners and recombiners instead of breakers.

“Breakers are great for applications with variable loads — plugging too many devices into an outlet, a hair dryer in a bathroom. In a solar application there aren’t any variable loads or hair dryers, so if an overcurrent protective device [OCPD] trips, there is a real problem, and resetting the OCPD is the least of your concerns,” he says. “Breakers degrade with every use, so the more times they are used as a disconnect, the more likely they are to nuisance trip at some later time when they shouldn’t.”

Four trends leading ground-mounted solar in 2018 from IHS Markit

As you get closer to the grid connection, interrupt ratings are higher. Fuses offer higher interrupt ratings and are more cost effective at these higher ratings than breakers.

“When a fuse is replaced, it will operate as it did when the original was new. A breaker on the other hand, after being reset, may not,” Schumacher says. “Breakers can also be more difficult to replace when they do eventually fail.”

Remember that every connection in a design is a source of contact resistance which generates heat, so one way to reduce potential for failure is to reduce those contact points. An example: Some systems are designed to connect the output lug to the copper bus bar using neutral bars attached with fasteners. This would mean one or more connections than is necessary and relies on small fasteners. Instead, SolarBOS uses a distribution block that directly connects to the incoming string wires and the output lug.

“Similarly, our positive bus bar typically connects to the next component directly with a bolted connection rather than using additional busbars or unreliable clamps,” Schumacher says. “Not only do all of these connections perform better, but there are fewer of them, which reduces the number of connections that need to be checked in maintenance efforts.”

— Solar Builder magazine

SolarBOS expands design services for large solar projects


SolarBOS has expanded its Design Services team to deliver additional services to customers in the large commercial and utility sectors of the solar industry. These services include wire layouts, takeoffs, detailed wire schedules and eBOS optimizations for systems larger than 1 MW.

“Providing detailed wire schedules helps ensure that every length is correct”, says product manager Zuzana Piras. “Manufacturing overmolded harnesses and wire bundles in house results in SolarBOS quality and short lead times.”

SolarBOS improves designs by leveraging experience from wire layouts on hundreds of sites and by using custom software to generate takeoffs from site-specific plans. SolarBOS manufactures 2-string and higher string count overmolded harnesses for all module types, including First Solar Series 6.

— Solar Builder magazine

Rapid Shutdown and Beyond: Inside NEC 2017 and the effort to streamline PV design

collaboration illustration

New codes and regulations are notorious for raising prices and halting innovation in industries, but the new rapid shutdown requirements facing the solar industry are having the opposite effect. Thanks to a coalition of manufacturers and interested parties across solar, the solutions being developed to meet NEC 2017 Module Level Rapid Shutdown requirements will achieve something solar technology has long needed: common language.

“The intent is to create an open protocol for any manufacturer to apply,” says Michael Mendik, head of solution management, Solar Energy Division at Fronius USA. He has been an active member of the SunSpec Alliance, the group that has developed these standards. “Inverter manufacturers can build and design their own transmitters and then the rapid shutdown boxes will also be tuned to that language and can receive the signal. There is no proprietary stuff.”

“The current systems were designed to meet the previous rapid shutdown requirements using mostly proprietary communication systems,” says Mario Thomas, product manager at ABB. “Future system design will be vendor independent, allowing a better choice for the customer and the installer.”

“The solar industry is experiencing significant growth with new requirements, so we welcome the vendor coordination efforts and the wide adoption by many vendors working to improve the safety of clean energy production,” says Danny Eizips, VP of engineering at Tigo. “This is a great opportunity for multivendor support.”

This standard protocol has ramifications beyond the context of rapid shutdown, but let’s start there.

NEC 2017 changes

The 2017 edition of the National Electrical Code (NEC 2017) includes an update to section 690.12 Rapid Shutdown of PV Systems on Buildings. The update pushes the requirement to “module-level” rapid shutdown instead of the “array level” that was listed in NEC 2014. Effective Jan. 1, 2019, this requires conductors inside the array boundary to be discharged to 80 volts or less within 30 seconds of initiating a rapid shutdown event. This requirement comes in addition to the outside the array boundary voltage being limited to 30 volts or less.

At first glance, the changes didn’t require such a collaborative effort. Module-level electronics could have done the trick and piecemeal proprietary products and one-off collaborations from various manufacturers could have continued as usual. Luckily, that wasn’t the case.

The SunSpec solution

Formed in 2009, the SunSpec Alliance is a trade alliance of more than 100 solar and storage distributed energy industry participants, together pursuing information standards to enable plug-and-play system interoperability.

After nearly two years of intense technical collaboration, the Communication Signal for Rapid Shutdown Interoperability Specification was published in September 2017 as a method to comply with NEC 2017. This spec defines a communication protocol that uses the cabling of the solar array to transmit messages over the DC power lines between the PV modules and a master control device located near the inverter.

In addition, PV module manufacturers can implement the protocol on intelligent devices embedded in the junction box of each PV module. A master control device associated with the inverter communicates with the PV modules. Altogether, the specification enables plug-and-play interoperability and any-to-any rapid shutdown solutions.

“This open standard delivers multiple benefits to the distributed energy industry, most notably lower integration costs and the freedom to choose from an array of interoperable products,” saysTom Tansy, chairman of the SunSpec Alliance.

What’s this mean for me right now?

  1. If you are a big fan of installing microinverters, you’re already meeting these rapid shutdown requirements.
  2. As mentioned earlier, the implementation date for NEC 2017 is Jan. 1, 2019. Depending on the Authority Having Jurisdiction where you do business, you may not even be held to the NEC 2014 requirement right now, let alone NEC 2017 when it arrives. The Northeast portion of the country will be the earliest adopters, followed by California.
  3. If you are going to be held to NEC 2017 — or just generally would like to comply on your own — sit back and wait for these SunSpec-certified products to hit the market and design systems the way you always have.

“The complexity here is not on the installer end,” Mendik says. Manufacturers had to develop a transmitter that’s hooked to the DC line and puts in the signal.

Some of these solutions are already available, like the Fronius Symo. Other companies announcing immediate plans to incorporate the technology into their product lines include ABB, Maxim Integrated, Omron, Outback, SMA and Tigo. You can expect to see most of these around Q2 this year. There is no UL testing protocol yet to certify these products, but UL is part of the SunSpec Alliance, and you can expect this to happen soon.

Why else is this a big deal?

Not to be flippant about the importance of safety, but this protocol opens the door for way more impactful product developments. There’s an opportunity here to make your life even easier and bring the costs of a system down even more.

1. Proprietary boundaries will come down.

For starters, the array-to-rapid-shutdown-box-to-inverter architecture is more flexible. Prior to any updates, you had to procure the rapid shutdown box and the inverter from the same manufacturer. No more.

“The installer can install the systems as before and doesn’t have to worry about matching inverters of rapid shutdown boxes,” Mendik says.
So, that’s cool, but that flexibility goes way beyond the rapid shutdown, inverter pairing. “There’s no specific [module-level electronics] on the roof,” Mendik continues. “If there are different panels, they will be working with different rapid shutdown boxes. If one type of inverter in a system breaks, it can be replaced with another, and it will still work. A distributor can have different inverter types in stock for replacement, and everything will still be in line with the protocol.”

2. System designs will be streamlined.

Today, that rapid shutdown box is just an added expense, even now, after the protocol. This is why many installers prefer module-level electronics like microinverters, which meet rapid shutdown module-level requirements while also adding optimization, monitoring and design flexibility.

In the not-too-distant future though, this rapid shutdown box will be gone completely, even in a string inverter design. Soon, using this common language, module manufacturers will be including supped up junction boxes or chips from a company like Maxim instead of diodes. These will meet NEC 2017 and provide MLE performance with a string inverter design. This will keep costs and industry part counts down.

“An integrated module in the future, where the installer doesn’t have to buy and wire a specific rapid shutdown box … it’ll be like going back in time to when he didn’t have to worry about that,” Mendik says. “This also means you won’t have complex electronics on the roof. The standard forces you into more complexity for rapid shutdown, but the solution we’re looking at is simple electronics, not power electronics and doesn’t convert power from DC to AC.”

Thomas sums it up: “The customer in the end has a choice. I think that’s a big benefit. Customers don’t want to get stuck with one vendor and want the right to choose between different manufacturers. Having this choice and competition will reduce costs in the end.”

— Solar Builder magazine