Fieldbus Solutions & Network Topologies. ISA Exhibition Toronto May 12, 2004

Transcription

1 Fieldbus Solutions & Network Topologies ISA Exhibition Toronto May 12, 2004

2 Fieldbus Solutions During this presentation we will talk about different network topologies and Fieldbus solutions for different applications. We will discuss the latest Fieldbus solutions for intrinsically safe, non-incendive and general purpose applications. Agenda With the recent increase in Fieldbus applications this short tutorial will highlight the wide range of solutions available to an Engineer installing a Fieldbus system.

3 Fieldbus Solutions Different Fieldbus applications require different solutions! Fieldbus Solutions General Purpose (no power limitations) Intrinsic safety (limited energy) - Non-incendive (Class I, Div.2) - Entity (Class I, Div.1) - FISCO (Class I, Div.1) Mixed applications

4 General Purpose Non-Incendive Intrinsically Safe Mixed Applications AGENDA Summary

5 General Purpose Control Room No power restrictions, products range from 350 ma to 1 Amp per segment Typically field devices/h1 segment Fieldbus Solutions es to connect devices to a trunk (no daisy chained connections) Power Repeaters are possible for longer cable runs and isolation Each segment must be terminated at both ends

6 General Purpose Red. Power Supply Active Active Active Control Room Higher level of security/availability! High power red. Power supply Fieldbus Solutions Short circuit protected, active junction boxes with built in selectable terminators A single short will not bring down an entire segment!

7

8 General Purpose Non-Incendive Intrinsically Safe AGENDA Mixed Applications Summary

9 Control Room Non-Incendive NI PS Class I, Div.2 NI PS NI PS More centralized architecture in this example Fieldbus Solutions Energy limited non-incendive trunk and spurs Simplifies wiring for Class I, Div.2 applications (no conduit) Can be used with NI, IS or FISCO field devices

10 Control Room Non-Incendive Class I, Div.2 Div.2 wiring method Redundant Power Hub Nonincendive outputs High Power Trunk with energy limited non-incendive spurs Fieldbus Solutions Taking true advantage of Fieldbus technology by using a distributed architecture Doesn t use up expensive control room real estate

11 Control Room Segment Protectors Segment Protectors, DIN-Rail mountable Power Supply Custom Field Enclosure Div.2 wiring method for trunk Nonincendive outputs Class I, Div.2

12 FNICO Fieldbus Non-Incendive ncendive COncept Based on FISCO with reduced factor of safety Reduced factor of safety allows more current into the Div.2 hazardous location (up to 215 ma available for up to 10 devices) FNICO is a non-incendive technique for Division 2 hazardous areas Simplified Div.2 wiring (no conduit etc.) when used with IS or FISCO field devices Live maintenance no hot work permit, just like Intrinsic Safety

13 FNICO Some Division 2 Definitions Non-arcing circuit: - may contain incendive levels of voltage and current - NOT live-workable - cables must be mechanically protected Non-incendive circuit - energy-limited to lower levels of voltage and current - like IS, but without fault counting and with lower safety factor - LIVE-workable under power When using FNICO power supplies, the trunk and spurs are non-incendive FNICO cable parameters are the same as for FISCO, spur length is 60m

14 Div.2 Mountable vs. Nonincendive Outputs Many devices are Div.2 mountable BUT not all Div. 2 mountable devices have nonincendive rated (energy limited) outputs! Check the marking on the product to make sure the outputs are energy limited and rated nonincendive Only nonincendive outputs are live workable!

15 General Purpose Non-Incendive Intrinsically Safe Mixed Applications Summary

16 Control Room Intrinsic Safety Class I, Div.1 Class I, Div.2 Energy Limited Intrinsically Safe Trunk and spurs Using the FISCO model: up to 6 devices on 1 power repeater vs. 4 for Entity Using n power repeaters n x 6 field devices Installable in Div. 2 to gain cable length

17 Intrinsic Safety Field Barrier Class I, Div.2 Field Barrier Control Room Class I, Div.1 Fieldbus Solutions Latest technology => Field barrier No power limitation for Trunk (non-is) True distributed architecture Combines the features of: - active junction box - with an IS barrier All in a field mountable package

18 Control Room FieldBarrier FieldBarriers, DIN-Rail mountable Power Supply Custom Field Enclosure Div.2 wiring method for trunk IS outputs (Zone 1,0 Class I, Div.1 A-D) Class I, Div.1 Zone 0

19 FIELDBUS INTRINSICALLY SAFE CONCEPT FISCO is in accordance with intrinsic safety world standards (Intrinsic safety according to EN50020 and IEC 79-11, Class I, Division 1 according to US-standards) Only one active source (power supply) per system The nodes act as passive current sinks Nodes have negligible internal inductance and capacitance (Li 10μH, Ci 5nF) Variety of cables with specified parameters can be used Max. cable length is 1000 m (3281 ft) Bus line is terminated at both ends Field devices and power source have to be in accordance with FISCO.

20 FISCO Model If you reach the previous preconditions the verification of intrinsic safety will be reduced to: Power Repeater Field device V 0C < U i I SC < I i P 0 < P i

21 Add all C i, L i of instruments Add cable L cable, C cable Compare all V max, I max of instruments and evaluate to parameters of power source Evaluate: V oc < V max I sc < I max (individually) P 0 < P i (individually) C a > C i + C cable L a > L i + L cable Entity Concept Difficult to do for fieldbus network! Very time consuming! FISCO is more user friendly!

22

23 General Purpose Non-Incendive Intrinsically Safe AGENDA Mixed Applications Summary

24 Control Room Mixed Applications Red. Power Supply Safe Area Active Fieldbus Solutions Field Barrier Class I, Div.1 Active Class I, Div.2

25 Mixed Applications IS and non-is segments can easily be mixed when using the proper interface devices Trunk cable runs can be longer and more secure when using a high reliable, redundant Fieldbus power supply IS protection (FISCO or Entity based) can be achieved when and where ever needed by using Field barriers or IS power repeaters/isolated power supplies in the field and close to the field instruments Fieldbus Solutions

26 General Purpose Non-Incendive Intrinsically Safe AGENDA Mixed Applications Summary

27 Summary/Questions Fieldbus Solutions Many different topologies are possible. In order to find the best solution it is important to determine: Is it a general purpose, IS, NI or mixed application? => It might be advantages to bring high power, red. Trunk into the field and use devices like field barriers or isolators to create IS protection where needed. Do I prefer a true distributed architecture? => limited control room space, field mountable interface devices! Do I have critical loops? => Redundant PS, short circuit protected junction boxes, higher availability

28 Thank you! Fieldbus Solutions