DART enables risk reduction
o Safest Fieldbus installation with power (all intrinsically safe)
o Working without hot work permit
o Same equipment for all gas groups (certified for gas group IIC)
o Reduced planning risks without special considerations for the hazardous area
o Protection of investment for intrinsically safe Fieldbus instrumentation
o Higher plant availability through built-in redundancy
DART lifts power limits
o Intrinsic safety with more power
o Long cable runs (up to 1,000m trunk and up to 120m spur)
o Optional advanced diagnostics for the physical layer
o Up to 32 instruments per segment
o Designed and conforms to standards for explosion protection IEC 60079-11
THE first real application for DART (Dynamic Arc Recognition and Termination) is DART Fieldbus. It is part of the FieldConnex series of Fieldbus infrastructure components by Pepperl+Fuchs.
DART Technology, which is also known as ‘Power-I’ and driven by a consortium of 13 companies, enables high power levels while maintaining ignition protection intrinsic safety (I.S.) – the safest way to protect plants in hazardous areas from unintended ignitions and explosions.
DART Fieldbus is made for hazardous area Zone 1 and gas group IIC. It is certified "by the book" through PTB, the German Metrology Institute, according to the standard that is familiar to hazardous area specialists: IEC 60079-11.
This results in the highest degree of protection in hazardous area Zone 1 through intrinsic safety.
Fieldbus instrumentation
Real simplicity is built into DART Fieldbus. It offers all the benefits of FISCO, the Fieldbus Intrinsically Safe Concept regarding engineering, application and maintenance.
Only DART Fieldbus enables more than five times the power of current intrinsically safe Fieldbus installations – enough to drive long cable lengths and many devices.
Ten years ago with FISCO, the acceptance of intrinsically safe Fieldbus began with rules simplifying application and validation of explosion protection. DART Fieldbus now breaks through even more barriers – lifting the power limits and offering the freedom of choice.
The intrinsically safe High-Power Trunk reaches with power into the hazardous area allowing long cable runs and offers all the benefits of FISCO.
Applied on upgrades
Existing intrinsically safe Fieldbus instrumentation can be applied or remains in place on upgrades.
"Our first idea for DART Fieldbus was to come up with a full Intrinsically Safe Fieldbus segment with the same attributes and power compared to Fieldbus in the safe area," says Michael Kessler, Technical Director, Components and Technology at Pepperl+Fuchs.
"This is why DART only protects the trunk. The spurs are intrinsically safe in the classic way. DART Fieldbus can be used for existing intrinsically safe instrumentation." The differences between DART Fieldbus and Fieldbus in safe areas are negligible.
Operating conditions
Other attributes include physical layer diagnostics and load-sharing redundancy of power supply.
Load sharing means that power supplies are controlled to carry exactly half the load current each.
This means optimal operating conditions, a longer service life of power supply and higher system availability.
DART Fieldbus may well become the best-in-class solution for intrinsically safe Fieldbus installations – it has the power, the options, and the experience from Pepperl+Fuchs, considered a specialist in hazardous area products.
Major innovation
DART has been recognised as a major innovation for the process industry and was one of the top five nominees for the Hermes Award of Hannover Fair in Germany.
Two years after the nomination, Pepperl+Fuchs has put this technology into practice and products.
Kessler remarks: "It fills us with pride to have been recognised in this way. We are looking to create a solution that is practical and easy to apply."
PepperlFuchs is a developer and manufacturer of electronic sensors and components for the global automation market.
[Andreas Henneckeis is Product Marketing Manager FieldConnex, Division Process Automation Division at Pepperl+Fuchs.]