1、 AMERICAN NATIONAL STANDARD ANSI/ISA-60079-27 (12.02.04)-2006 Fieldbus Intrinsically Safe Concept (FISCO) and Fieldbus Non-Incendive Concept (FNICO) Approved 29 January 2007 ANSI/ISA-60079-27 (12.02.04)-2006, Fieldbus intrinsically safe concept (FISCO) and Fieldbus non-incendive concept (FNICO) ISBN
2、: 978-1-55617-971-6 Copyright 2006 by IEC and ISA. All rights reserved. Printed in the United States of America. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise), w
3、ithout the prior written permission of the Publisher. ISA 67 Alexander Drive P. O. Box 12277 Research Triangle Park, North Carolina 27709 USA 3 ANSI/ISA-60079-27 (12.02.04)-2006 Preface This preface, as well as all footnotes and annexes, is included for information purposes and is not part of ANSI/I
4、SA-60079-27 (12.02.04)-2006. This document has been prepared as part of the service of ISA toward a goal of uniformity in the field of instrumentation. To be of real value, this document should not be static but should be subject to periodic review. Toward this end, the Society welcomes all comments
5、 and criticisms and asks that they be addressed to the Secretary, Standards and Practices Board; ISA; 67 Alexander Drive; P. O. Box 12277; Research Triangle Park, NC 27709; Telephone (919) 549-8411; Fax (919) 549-8288; E-mail: standardsisa.org. The ISA Standards and Practices Department is aware of
6、the growing need for attention to the metric system of units in general, and the International System of Units (SI) in particular, in the preparation of instrumentation standards. The Department is further aware of the benefits to USA users of ISA standards of incorporating suitable references to th
7、e SI (and the metric system) in their business and professional dealings with other countries. Toward this end, this Department will endeavor to introduce SI-acceptable metric units in all new and revised standards, recommended practices, and technical reports to the greatest extent possible. Standa
8、rd for Use of the International System of Units (SI): The Modern Metric System, published by the American Society for Testing b) the bus terminals shall be isolated from earth ground in accordance with ANSI/ISA-60079-11 IEC 60079-11; 15 ANSI/ISA-60079-27 (12.02.04)-2006 c) the bus terminals of separ
9、ately powered field devices shall be galvanically isolated so as to ensure that these terminals remain passive and multiple earthing grounding of the bus is avoided; d) the maximum unprotected internal capacitance Ciof each field device shall not be greater than 5 nF. No specification of the input a
10、nd internal parameters is required on the certificate, control drawing or label. 5.2 FISCO field devices The additional requirements of FISCO field devices are as follows: a) apparatus shall have minimum input parameters of Ii: 380 mA and Pi: 5,32 W; b) apparatus shall have a internal inductance Lin
11、ot greater than 10 H; c) under normal or fault conditions as specified in ANSI/ISA-60079-11 IEC 60079-11 the bus terminals shall remain passive, i.e. the terminals shall not be a source of energy to the system except for a leakage current not greater than 50 A; d) field devices shall be allocated a
12、category, be suitable for IIC apparatus group and temperature classified and constructed in accordance with ANSI/ISA-60079-11 for apparatus group IIC IEC 60079-11; e) the apparatus documentation shall state that the apparatus is suitable for use in a FISCO system in accordance with this standard. 5.
13、3 FNICO field devices The additional requirements for FNICO field devices are as follows: a) apparatus shall have an internal inductance Li not greater than 20 H; b) under normal conditions as specified in ANSI/ISA-60079-15 IEC 60079-15, the bus terminals shall remain passive, i.e. the terminals sha
14、ll not be a source of energy to the system except for a leakage current not greater than 50 A; c) field devices shall be suitable for IIC apparatus group and temperature classified and constructed in accordance with ANSI/ISA-60079-15 for apparatus group IIC and IEC 60079-15 with the protection type
15、nL nC in accordance with Clause 22 of ANSI/ISA-60079-15 at the bus terminals; NOTE: At the time that this standard was prepared, the National Electrical Codedid not recognize protection type “nL”. d) the control drawing apparatus documentation shall state that the apparatus is suitable for use in a
16、FNICO system in accordance with this standard. 6 Terminator 6.1 General The line terminators required by the system shall comprise a resistor-capacitor combination which presents at its terminals a circuit equivalent to a resistor of value 90 to 102 in series with a capacitor of 0 F to 2,2 F (includ
17、ing tolerances). NOTE 1 IEC 61158-2 requires an operational capacitance value of 0,8 F to 1,2 F. The terminator shall ANSI/ISA-60079-27 (12.02.04)-2006 - 16 - a) have minimum input parameters of Ui: 17,5 V; b) be isolated from earth ground in accordance with ANSI/ISA-60079-11 IEC 60079-11; c) have a
18、 maximum unprotected internal inductance Linot greater than 10 H. The terminators may be incorporated within field devices or power supplies. NOTE 2 For safety assessment purposes the effective capacitance of the terminator Ciis considered not to affect the intrinsic safety or incendivity of the sys
19、tem. 6.2 FISCO terminator The additional requirements are that a FISCO terminator shall a) have minimum input parameters of Ii: 380 mA and Pi: 5,32 W; b) be allocated a category, be suitable for apparatus group IIC and be temperature classified and constructed in accordance with ANSI/ISA-60079-11 IE
20、C 60079-11. The terminator control drawing documentation shall state that the terminator is suitable for use in a FISCO system in accordance with this standard. 6.3 FNICO terminator The additional requirements are that a FNICO terminator shall be suitable for apparatus group IIC and be temperature c
21、lassified and constructed in accordance with ANSI/ISA-60079-15 IEC 60079-15 nL nC apparatus. The terminator control drawing documentation shall state that the terminator is suitable for use in a FNICO system in accordance with this standard. 7 System requirements 7.1 General A system is usually of t
22、he form illustrated in Figure 1. The cable used in the system shall comply with the following parameters: loop resistance Rc15 /km to 150 /km; loop inductance Lc0,4 mH/km to 1 mH/ km; capacitance Cc45 nF/km to 200 nF/km; maximum length of each spur cable 60 m in IIC and IIB; maximum length of each t
23、runk cable, including the length of all spurs, 1 km in IIC and 5 km in IIB. When the cable, which complies with this standard, is used, no further consideration of cable parameters is necessary. The cable parameters may be determined in accordance with Annex C of IEC 60079-14. Where a system compris
24、es one source of power, 17 ANSI/ISA-60079-27 (12.02.04)-2006 any number of field devices up to 32, and two terminators, all complying with the requirements of this standard combined with a cable to the above specification, then that system shall be considered to be adequately safe. The two terminato
25、rs shall be situated at the ends of the trunk. The power supply shall be located not more than 30 m from one end of the trunk. Where the power supply is connected via a spur, then that spur is restricted to a length of 30 m. NOTE The number of field devices which can be connected to a spur is not re
26、stricted by consideration of explosion safety but may be restricted by operational constraints. Connection facilities and/or switches may be added to a system without modifying the safety assessment. The safety documentation may be simplified to a list of the equipment, together with relevant appara
27、tus documentation used. NOTE 1: The control drawing should comply with the applicable requirements of ISA-RP12.02.02 NOTE 2: The apparatus group of the power supply determines the apparatus group of the system. NOTE 3: The temperature classification of each piece of apparatus should shall be determi
28、ned by its certification. It is also necessary to confirm that the permitted maximum ambient temperature of each piece of apparatus is suitable for its intended location. 7.2 FISCO system requirements The power supply and all field devices and terminators used in a FISCO system must comply with the
29、FISCO requirements of this standard and be marked with FISCO. When such apparatus is combined in a system in accordance with this standard, no further consideration of the suitability of the apparatus is required. The system will have a level of protection category (ia or ib) determined by the field
30、 devices, terminators, apparatus and power supply used. NOTE: Sub-systems of the system may have different categories where this can be justified by the assessment. For example, an ia spur may be created from an ib trunk by the insertion of a suitably certified interface. The safety documentation co
31、ntrol drawing shall clearly identify the category of each part of a system. 7.3 FNICO system requirements Power supplies, field devices and terminators and other ancillaries complying with the FISCO requirements of this standard may also be used in a FNICO system. Field devices, terminators and othe
32、r ancillaries complying with the requirements of intrinsic safety but not as FISCO apparatus in accordance with this standard may be used with a FNICO power supply in a FNICO system provided that they have input parameters of Uinot less than 17,5 V and internal parameters of Liand Cinot greater than
33、 20 H and 5 nF respectively Similarly, apparatus not approved as FNICO apparatus, but constructed in accordance with the requirements of IEC 60079-15 nL apparatus and having input parameters of Uinot less than 17,5 V and internal parameters of Liand Cinot greater than 20 H and 5 nF respectively, may
34、 be used in a FNICO system. The control drawing shall clearly identify the category of each part of a system. ANSI/ISA-60079-27 (12.02.04)-2006 - 18 - NOTE: Where intrinsically safe or type nC nL apparatus is used in a FNICO system, this should be indicated at the point of installation. A plant labe
35、l marked FNICO AEx nCL system is an acceptable way of satisfying this requirement. 8 Marking 8.1 FISCO marking Each piece of apparatus shall be marked with the word “FISCO“ followed by an indication of its function, i.e. power supply, field device or terminator. In addition, each piece of apparatus
36、shall be marked in accordance with ANSI/ISA-60079-11 IEC 60079-11, except where modified by this standard. For example, the manufacturers name and address must still be marked. Where apparatus is dual marked so that it can be used in both a FISCO system and a conventional intrinsically safe system,
37、care shall be taken to differentiate between the FISCO marking and the marking for the intrinsically safe system. The marking of apparatus for use in either a FISCO system or a conventional intrinsically safe system shall differentiate between the FISCO marking and the marking for the intrinsically
38、safe system. For FISCO power supplies, output parameters Uo, Io, Co, Lo, Poand Lo/Roneed not be marked. For FISCO field devices or terminators, input and internal parameters Ui, Ii, Ci, Li, Pi and Li/Rineed not be marked. 8.2 FNICO marking Each piece of apparatus shall be marked with the word “FNICO
39、“ followed by an indication of its function, i.e. power supply, field device or terminator. In addition, each piece of apparatus shall be marked in accordance with ANSI/ISA-60079-15 IEC 60079-15, except where modified by this standard. The marking of apparatus for use in either a FNICO system or a c
40、onventional nonincendive field wiring system shall differentiate between the FNICO marking and the marking for the nonincendive field wiring. For FNICO power supplies, output parameters Uo, Io, Co, Lo, Poand Lo/Roneed not be marked. For FNICO field devices or terminators, input and internal paramete
41、rs Ui, Ii, Ci, Li, Pi and Li/Rineed not be marked. 9 Examples of marking 9.1 Examples of FISCO marking a) Power supply FISCO power supply Um: 250 V AEx ia IIC John Jones Ltd SW99 2AJ UK Type: DRG OOI 20 C Ta +50 C 19 ANSI/ISA-60079-27 (12.02.04)-2006 PTB Nr 01A 2341 Serial No: 014321 Control Drawing
42、 JJDRG001 b) Field device FISCO field device Class I Zone 0 AEx ia IIC T4 Paul McGregor plc GL99 1JA UK Type: RWS 001 20 C Ta +60 C INERIS 01 A 1234 Serial No 013241 Control Drawing PM0165 c) Terminator FISCO terminator Cl I Zn 0 AEx ia IIC T4 James Bond plc MK45 6BY UK Type MI5 007 BAS 01 A 4321 Se
43、rial No: 012345 Control Drawing P45 d) Dual marked field device A McTavish plc GL 98 1BA UK Type RWS 002 20 C Ta +60 C INERIS 02 A 2345 Serial No: 060128 - - - - - - - - - - - - - - - - FISCO Field device Class I Zone 0 AEx ia IIC T4 Control Drawing MT002 - - - - - - - - - - - - - - - - Class I Zone
44、 0 AEx ia IIC T6 Ui: 28 V ANSI/ISA-60079-27 (12.02.04)-2006 - 20 - Ci: 3 nF Ii: 200 mA Li: 10 H Pi: 1,2 W Control Drawing MT003 9.2 Examples of FNICO marking a) Power supply FNICO power supply AEx nAL IIC John Jones Ltd SW99 2AJ UK Type: DRG OO2 20 C Ta +50 C PTB Nr 01A 3412 Serial No: 015321 Contro
45、l Drawing JJDRG002 b) Field device FNICO field device Class I Zone 2 AEx nAL IIC T4 Paul McGregor plc GL99 1JA UK Type: RWS 002 20 C Ta +60 C INERIS 01 A 1234 Serial No 023241 Control Drawing PM0169 c) Terminator FNICO terminator Class I Zone 2 AEx nAL IIC T4 James Bond plc MK45 6BY UK Type MI5 008
46、BAS 03 A 4321 Serial No: 022341 Control Drawing P58 21 ANSI/ISA-60079-27 (12.02.04)-2006 10 System diagram 5 UI 2 3 1 1467 Hazardous area UNon-hazardous area IEC 510/05 Key 1 Terminator 5 Field devices 2 Power supply 6 Trunk 3 Data 7 Spur 4 Hand held terminal Figure 1 Typical system _ This page inte
47、ntionally left blank. 23 ANSI/ISA-60079-27 (12.02.04)-2006 Annex A (informative) United States major deviations NOTE: The text of Annex A has been added. The underlining has been omitted for clarity. General. IEC references have been replaced with US standard references where possible. 3.4 The defin
48、ition for control drawing has been added. 4.1 A deviation to allow a reduction in the number of faults in wiring for FNICO systems has been added to align with ANSI/ISA-12.12.01. 5.3c) The National Electrical Code does not recognize the term “nL” and therefore the alternative code “nC” which is reco
49、gnized, has been used, together with a reference to the applicable clauses of ANSI/ISA-60079-15. 8.2 A requirement to differentiate between FNICO and nonincendive field wiring has been added. This page intentionally left blank. Developing and promulgating sound consensus standards, recommended practices, and technical reports is one of ISAs primary goals. To achieve this goal the Standards and Practices Department relies on the technical expertise and efforts of volunteer committee m
