European debut of intrinsic safety breakthrough

For 40 years intrinsic safety (EX i) has meant limiting the amount of electric power to less than 2 Watts in dangerous areas, for fear any spark could ignite an explosion. As a result, an entire industry of companies has developed that supply isolators and barriers to provide this type of protection.

07/01/2008


For 40 years intrinsic safety (EX i) has meant limiting the amount of electric power to less than 2 Watts in dangerous areas, for fear any spark could ignite an explosion. As a result, an entire industry of companies has developed that supply isolators and barriers to provide this type of protection. At Interkama, one of the co-located shows that was part of Hannover Industrial Fair this year, two of these companies were showing a new approach that could potentially alter the future of EX i practice.

MTL Instruments Group, based in Luton, England, U.K., and Pepperl + Fuchs, with world headquarters in Mannheim, Germany, were displaying technology that allows comparatively large amounts of power—50 Watts and beyond—into areas that were previously considered too dangerous for live electricity.

The new method uses fast electronics to monitor fieldbus circuits and detect surges in current and voltage that are characteristic of a suddenly broken line or a module being unplugged from a backplane.

Sparks always lead to a sudden peak of the current and voltage within the respective circuit, and these peaks show very specific characteristics. Electronics can detect those characteristics within five microseconds and shut down the power supply. The idea is to shut off power before a critical situation can arise, and before the current can reach a level to build up sufficient heat for ignition.

For its efforts, Pepperl+Fuchs was one of five Hermes Award finalists at Hannover Messe (winners of the Hermes Award, the world's largest technology prize, receive 100,000 Euros). Its system is called DART, for dynamic arc recognition and termination.

Dipl-Ing Thomas Kleinbongartz, Pepperl+Fuchs director of global marketing, says his company will offer DART in two versions: one is for high-power devices up to 50 Watts inside the Ex i area, such as industrial PCs, LED lighting systems, analysis instruments, and solenoid valves. A second system will offer, via a fieldbus infrastructure, up to 8 Watts of electric power per segment inside explosion hazardous areas.

Factors such as cable length and device characteristics can greatly influence the response time for spark detection, says Kleinbongartz. DART deals with these differences by connecting the device via a decoupling module to the energy supply. The module ensures a clearly defined electrical response pattern, always providing the DART system with a signal that allows the dependable detection of critical situations requiring immediate shutdown of the circuit, he said.

MTL Instruments Group managing director Graeme Philp was on hand to introduce his company's version of the concept called “Fast Switch.” MTL will implement the technology in conjunction with the MTL PoEx Intrinsic Safety Ethernet range, which was a major product launch at Interkama.

“The ability to run fieldbus networks over a longer distance while maintaining the ability to live work is solved by the use of certified switching components that permit the safe interruption of non-intrinsically safe circuits,” Philp said. “This, together with the launch at Interkama of redundant power for FISCO (Fieldbus Intrinsically Safe Concept) networks, allows users to enjoy the highest availability on the market, while retaining the ability to live work in applications requiring long cable lengths.”

At a Fieldbus Foundation seminar in Houston, TX, also in April 2008, Philp showed MTL's F809F Fieldbus diagnostics module. At that time, MTL Instruments was three months into its acquisition by U.S.-based Cooper Industries and Philp told Control Engineering , “It's really going well. This purchase has not limited our independence.” Philp characterizes the transition as highly complementary and beneficial for customers. “There's not a single product overlap,” he said.



Author Information

Michael Babb is editor of Control Engineering Europe. Reach him through




No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
Your leaks start here: Take a disciplined approach with your hydraulic system; U.S. presence at Hannover Messe a rousing success
Hannover Messe 2016: Taking hold of the future - Partner Country status spotlights U.S. manufacturing; Honoring manufacturing excellence: The 2015 Product of the Year Winners
Inside IIoT: How technology, strategy can improve your operation; Dry media or web scrubber?; Six steps to design a PM program
Getting to the bottom of subsea repairs: Older pipelines need more attention, and operators need a repair strategy; OTC preview; Offshore production difficult - and crucial
Digital oilfields: Integrated HMI/SCADA systems enable smarter data acquisition; Real-world impact of simulation; Electric actuator technology prospers in production fields
Special report: U.S. natural gas; LNG transport technologies evolve to meet market demand; Understanding new methane regulations; Predictive maintenance for gas pipeline compressors
Warehouse winter comfort: The HTHV solution; Cooling with natural gas; Plastics industry booming
Managing automation upgrades, retrofits; Making technical, business sense; Ensuring network cyber security
Designing generator systems; Using online commissioning tools; Selective coordination best practices

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
This article collection contains several articles on the vital role that compressed air plays in manufacturing plants.
This article collection contains several articles on the Industrial Internet of Things (IIoT) and how it is transforming manufacturing.
This article collection contains several articles on strategic maintenance and understanding all the parts of your plant.
click me