User's Manual
Table Of Contents
- SITRANS LR250 (PROFIBUS PA)
- Legal information
- Table of contents
- 1 Introduction
- 2 Safety notes
- 3 Description
- 4 Installing/mounting
- 5 Connecting
- 6 Commissioning
- 7 Remote operation
- 8 Parameter reference
- 9 Service and maintenance
- 10 Diagnosing and troubleshooting
- 11 Technical data
- 12 Dimension drawings
- 12.1 Threaded horn antenna
- 12.2 Threaded horn antenna with extension
- 12.3 Flanged horn antenna
- 12.4 Flanged horn antenna with extension
- 12.5 Flanged encapsulated antenna (2"/DN50/50A sizes only)
- 12.6 Flanged encapsulated antenna (3"/DN80/80A sizes and larger)
- 12.7 Threaded PVDF antenna
- 12.8 Threaded connection markings
- 12.9 Raised-Face flange per EN 1092-1 for flanged horn antenna
- 12.10 Raised-Face flange per EN 1092-1 for flanged encapsulated antenna
- 12.11 Flat-Face flange
- 12.12 Process connection tag (pressure rated versions)
- A Appendix A: Technical reference
- B Appendix B: PROFIBUS PA profile structure
- C Appendix C: Communications via PROFIBUS
- D Appendix D: Certificates and Support
- 13 List of abbreviations
- 14 LCD menu structure
- Glossary
- Index

Connecting
5.3 Wiring setups for hazardous area installations
SITRANS LR250 (PROFIBUS PA)
Operating Instructions, 01/2014, A5E32221386-AB
31
Entity concept:
The Entity Concept allows interconnection of intrinsically safe apparatus to associated apparatus
not specifically examined in such combination. The criteria for interconnection is that the voltage
and current which intrinsically safe apparatus can receive and remain intrinsically safe,
considering faults, must be equal to or greater than the output voltage (Uo) and output current
(Io) 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 the
intrinsically safe apparatus, including interconnecting wiring, must be equal to or less than the
capacitance and inductance which can be safely connected to associated apparatus.
Under the entity evaluation concept, SITRANS LR250 has the following characteristics:
(input voltage) U
i
= 24 V
(input current) I
i
= 250 mA
(input power) P
i
= 1.2 W
(internal capacitance) Ci
= 0
(internal inductance) Li
= 0