Siemens sitrans PROBE LU User Manual

Page 104 SITRANS Probe LU (PROFIBUS PA) – INSTRUCTION MANUAL 7ML19985JB02
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J: Hazardous installation
FISCO-Concept
The FISCO Concept allows interconnection of intrinsically safe apparatus to associated
apparatus not specifically examined in such combination. The criteria for interconnection
is that the voltage (Ui or Vmax), the current (Ii, or Imax) and the power (Pi, or Pmax) which
intrinsically safe apparatus can receive and remain intrinsically safe, considering faults,
must be equal to or greater than the voltage (Uo or Voc or Vi), the current (lo or Isc or li),
and the power (Po or Pmax) levels which can be delivered by the associated apparatus,
considering faults and applicable factors. In addition, the maximum unprotected
capacitance (Ci) and inductance (Li) of each apparatus (other than the termination)
connected to the fieldbus must be less than or equal to 5 nF and 10 µH respectively.
In each segment only one active device, normally the associated apparatus, is allowed to
provide the necessary energy for the fieldbus system. The allowed voltage Uo (or Voc or
Vt) of the associated apparatus is limited to the range of 14V DC to 24V DC. All other
equipment connected to the bus cable has to be passive, meaning that they are not
allowed to provide energy to the system, except to a leakage current of 50 µA for each
connected device. Separately powered equipment needs a galvanic isolation to assure
that the intrinsically safe fieldbus circuit remains passive.
FM/CSA
• Approved dust-tight and water-tight conduit seals are required for outdoor
NEMA 4X / type 4X / NEMA 6, IP67, IP68 locations.
• The maximum voltage of the non-intrinsically safe apparatus must not exceed 250 V rms.
Note: For complete details and instructions regarding the FISCO Concept, see page
Intrinsically Safe wiring drawing (FM/CSA) on page 107 for drawing number 23650617,
also available from the product page of our website: www.siemens.com/
processautomation.
EEx ia type
DP/PA coupler
Active PLC
Non-hazardous area
Hazardous area
Zone 0, 1,
or 2
EEx ia
P
D
M

Siemens sitrans PROBE LU Specifications

General

Measuring Principle	Ultrasonic
Communication	HART
Output	4 to 20 mA
Power Supply	12 to 30 V DC
Process Temperature	-40 to 80 °C
Enclosure Rating	IP68
Material	PVDF
Ambient Temperature	-40 to 70 °C
Measurement Range	0.25 to 12 m (0.8 to 39 ft)