If a car doesn't have wheels it will always stop.
So, explosion proof...
Put it in a box.
Fill it full of sand.
so, how do you get what the customer wants: safety at better performance.
What the customer wants is better brakes.
Dynamic Arc Recognition and Termination: DART
"A paradigm shift in intrinsic safety installations," Bolin said.
Principle of classic instrinsic safety is to limit voltage, current, power, inductance and capacity in an intrinsically safe system to a constand value. See "ignition curves." Stay below the curves and you're safe.
Zener diode, resistor, and a fuse. That's a static fixed approach.
The future of intrinsic safety-- DART
developed and approved by PTB in Braunschweig.
The principle of DART is the detection of the developing arc and the fast shut down of power before ignition occurs.
Time to shut off power: 5 to 10 usecond.
Mapping the physical behavior of a spark---rapid drop in current, rapid rise in voltage, voltage starts to climb, current continues to fall, and there is an explosion.
DART senses the initial phase of the generation of a spark.
DART can allow you to operate an intrinsically safe device at much higher power than current standard IS equipment.
Bolin compares DART to standard power, and then to FISCO Fieldbus. In a 1000m cable DART can operate at 24 vdc at 8w, while FISCO operates at 12.8 vdc at about 1.4 watts.
DART will be released for Foundation Fieldbus this year.
DART cannot be rated for Div I NORTH AMERICA. It works in Zone applications, outside North America.
The DART high power trunk provides more ca ble distance with a higher device count and the same installation throughout-- and it makes hot work on supplies, couplers, devices practical.
DART protects the trunk:
-extinguishes the spark before it ecomes incendive
live disconnect permitted without hot work permit
provides intrinsically safe three-portisolation
power redundancy with true load sharing.
Overall cable length can be 1900 m.
48 spurs on an IS segment!!!
Same size poer supply. Much smaller field cabinet.
Existing equipment may be used.
Meets IEC 60079