A Flash of Inspiration
Rarely do beauty and danger lie as closely together as in this natural wonder: As impressive as the bolts of lightning that illuminate the sky may be, the consequences of a lightning strike can be devastating. Driven by fascination for this natural phenomenon, along with experience, ambition, and a few “flashes” of inspiration along the way, Pepperl+Fuchs has developed a 6.2-mm-wide plug-in surge protection system that offers much more than just protection.
It’s hard to believe but true—Roy C. Sullivan, a former ranger at an American national park, was struck by lightning an incredible eight times during his lifetime and walked away each time with only minor injuries. This earned him an entry in Guinness World Records. Statistics on the international occurrence of thunderstorms are equally incredible: Experts estimate that, at any given point in time, there are 2,000 to 3,000 thunderstorms worldwide accompanied by up to 30 million flashes of lightning each day. Most lightning strikes occur in regions in South America, along the equator in Africa, and in Asia. “So it’s no surprise that the first impulses to work on the subject of lightning and surge protection came from Asia,” says Friedrich Füß, Product Portfolio Manager for Interface Technology at Pepperl+Fuchs in Mannheim.
It is the sum of the additional functions that makes the new surge protection module so special.
“Initial Spark” After Lightning Strikes
One of his first research trips led him to Asia, to the Institute for Surge Protection in Shanghai. “The Institute is a leading authority in China,” explains Füß. “There, damage caused by surges from large lighting strikes is well known because people have personal experience with strong storms and have to deal with the consequences.” He also got a taste of this himself: His appointment at the institute was canceled because the director he was supposed to meet with was called to investigate a lightning strike on a soccer field that had fatal consequences.
Despite this, or indeed because of it, Füß was undeterred in his pursuit of the topic, and he dedicated himself to assembling a team that came to be true experts in surge protection. “The features that we have developed in minimal space for the new M-LB-5000 (Modular Lightning Barrier) surge protection system were only possible thanks to the wealth of ideas from a highly motivated group. The five-man core team, along with about 25 colleagues from production, purchasing, engineering, and service, has achieved great things,” sums up Füß.
Surges—The Most Underestimated Cause of Damage
Lightning discharges within ten microseconds, creating currents of up to 100,000 amps and several million volts and can immediately heat the surrounding air to up to 30,000 °C—the equivalent of more than five times the surface temperature of the sun. If such a force of nature hits unprotected industrial plants, it can have disastrous consequences: fires, damage to electronics, failure of entire automation systems, and damage to or the complete destruction of the plants and buildings—to say nothing of the danger to human life.
“The probability of a direct lightning strike is fortunately extremely low, but this is only the tip of the iceberg,” explains Thomas Lebkücher, Head of the Mechanical Design Product Group for process automation at Pepperl+Fuchs in Mannheim. “The impact of an indirect lightning strike is frequently underestimated. Even if a flash is a few hundred meters away, voltage peaks can bring the entire electrical system to a standstill. Overvoltages caused by direct or indirect lightning strikes, but also due to switching operations, are therefore still one of the most common causes of damage in electrical systems.”
For these reasons, modern surge protection is an investment in increased operational reliability and plant availability. But how is the protective equipment designed, and what has to be considered during implementation to create as much added value as possible for the user?
One Serious Requirements Profile
DIN-rail-mountable surge protection for measurement and control signals was the basic requirement but by no means the biggest challenge. “It is the sum of the additional functions that makes the new surge protection module so special,” says Füß. “For our customers, surge protection cannot take up any additional space on the DIN rail. It must all be easily set up without special tools and must also indicate wear or failure on its own. Ideally, no expert knowledge should be necessary for maintenance—and a surge protection system should go practically unnoticed in the overall operation of the plant,” says Thomas Ofenloch, Development Engineer for Interface Technology at Pepperl+Fuchs in Mannheim.
This module is one of the most sophisticated and innovative products that I have ever helped develop.
Creativity was also required, so key issues were worked out in a series of brainstorming sessions, particularly with regard to integrating the required functions into a module that is just 6.2 mm wide. “Based on 20 years of experience, we have built up extensive expertise in surge protection complemented by long-standing expertise in explosion protection, analog technology, and interface modules,” says Lebkücher. What’s more, all the stops were pulled out: “Even during the design phase, we made video recordings with high-speed cameras to analyze the behavior of high-current contacts during a surge,” reports Project Manager Ofenloch. “With 50,000 images per second, it was possible to precisely identify every little detail, so we could build on this to optimize the number and arrangement of contacts.”
Close collaboration with colleagues at the production site in Singapore also played a key role in the successful development. “This was immensely important for the production-optimized development of the surge protection system,” emphasizes Ofenloch. And Lebkücher enthusiastically adds: “This module is one of the most sophisticated and innovative products that I have ever helped develop.”
Challenges Mastered Every Step of the Way
Even if some things didn’t go according to plan, as is common in most development projects, perseverance has paid off. The whole team agrees: “We were able to overcome our challenges without having to make compromises. From system designers to service technicians—the new surge protection system offers advantages throughout the entire user chain. To know that something that was believed to be impossible is possible after all provides a big confidence boost for our next projects.”
Since European users and standards bodies are also becoming increasingly aware of surge protection, it won’t be long before a new set of challenges arises.
To know that something that was believed to be impossible is possible after all provides a big confidence boost for our next projects.
The Benchmark in Surge Protection: The M-LB-5000 System
Surge protection in a modular design, packed into a space-saving housing and equipped with a patented diagnostic function—the M-LB-5000 system demonstrates cutting-edge technology in industrial surge protection. It consists of a base module that is integrated directly into the signal circuit and a plug-in protection module. At just 6.2 millimeters wide, both form an extremely narrow plug-in surge protection module. The integrated diagnostic function is also a unique feature—the module signals its own wear status both in the switch cabinet, via an easy-to-read traffic light indicator, and on the control panel, and gives a warning before a possible failure. This makes it easy to check the surge protection system in accordance with EN 62305-3, to significantly reduce product lifecycle costs, and to plan service calls in advance. An integrated isolation function makes it possible to run insulation testing during commissioning and to swap out modules during operation.