1、 RECOMMENDED PRACTICE ISA-RP12.06.01-2003 Recommended Practice for Wiring Methods For Hazardous (Classified) Locations Instrumentation Part 1: Intrinsic Safety Approved 16 April 2003 ISA-RP12.06.01-2003 Recommended Practice for Wiring Methods for Hazardous (Classified) Locations Instrumentation Part
2、 1: Intrinsic Safety ISBN: 978-1-55617-865-8 Copyright 2003 by ISA The Instrumentation, Systems, and Automation Society. All rights reserved. Not for resale. Printed in the United States of America. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any fo
3、rm or by any means (electronic mechanical, photocopying, recording, or otherwise), without the prior written permission of the Publisher. ISA 67 Alexander Drive P.O. Box 12277 Research Triangle Park, North Carolina 27709 3 ISA-RP12.06.01-2003 Copyright 2003 ISA. All rights reserved. Preface This pre
4、face, as well as all footnotes and annexes, is included for information purposes and is not part of ISA-RP12.06.01-2003. This document has been prepared as part of the service of ISAthe Instrumentation, Systems, and Automation Societytoward a goal of uniformity in the field of instrumentation. To be
5、 of real value, this document should not be static but should be subject to periodic review. Toward this end, the Society welcomes all comments 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
6、Park, NC 27709; Telephone (919) 549-8411; Fax (919) 549-8288; E-mail: standardsisa.org. The ISA Standards and Practices Department is aware of 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 inst
7、rumentation standards. The Department is further aware of the benefits to USA users of ISA standards of incorporating suitable references to the SI (and the metric system) in their business and professional dealings with other countries. Toward this end, this Department will endeavor to introduce SI
8、-acceptable metric units in all new and revised standards, recommended practices, and technical reports to the greatest extent possible. Standard for Use of the International System of Units (SI): The Modern Metric System, published by the American Society for Testing or b) apply to the use of porta
9、ble equipment, except as shown on the control drawing. 3 Definitions For purposes of this recommended practice, the following definitions apply: 3.1 approved: acceptable to the authority having jurisdiction (for additional information, see NEC Article 100). 3.2 associated apparatus: Associated Appar
10、atus: Apparatus in which the circuits are not necessarily intrinsically safe themselves, but that affect the energy in the intrinsically safe circuits and are relied on to maintain intrinsic safety. Associated apparatus may be either of the following: ISA-RP12.06.01-2003 10 Copyright 2003 ISA. All r
11、ights reserved. 1. Electrical apparatus that has an alternative-type protection for use in the appropriate hazardous (classified) location, or 2. Electrical apparatus not so protected that shall not be used within a hazardous (classified) location. FPN No. 1: Associated apparatus has identified intr
12、insically safe connections for intrinsically safe apparatus and also may have connections for nonintrinsically safe apparatus. FPN No. 2: An example of associated apparatus is an intrinsic safety barrier, which is a network designed to limit the energy (voltage and current) available to the protecte
13、d circuit in the hazardous (classified) location, under specified fault conditions. 3.3 authority having jurisdiction (AHJ): the organization, office, or individual responsible for approving equipment, materials, an installation, or a procedure. 3.4 channel: an ungrounded conductor in a grounded int
14、rinsically safe circuit, or a conductor and its reference in a galvanically isolated intrinsically safe circuit. 3.5 control drawing: Control Drawing: A drawing or other document provided by the manufacturer of the intrinsically safe or associated apparatus, or of the nonincendive field wiring appar
15、atus or associated nonincendive field wiring apparatus, that details the allowed interconnections between the intrinsically safe and associated apparatus or between the nonincendive field wiring apparatus or associated nonincendive field wiring apparatus. 3.6 corrective maintenance: any maintenance
16、activity that is not normal in the operation of equipment and requires access to the equipments interior. Such activities are expected to be performed by qualified personnel who are aware of the hazards involved. Such activities typically include locating causes of faulty performance, replacement of
17、 defective components (see 6.2.1), adjustment of internal controls, and the like. Corrective maintenance is referred to simply as maintenance in clause 6. 3.7 different intrinsically safe circuits: Different Intrinsically Safe Circuits: Intrinsically safe circuits in which the possible interconnecti
18、ons have not been evaluated and identified as intrinsically safe. 3.8 entity evaluation: a method used to determine acceptable combinations of intrinsically safe apparatus and connected associated apparatus that have not been investigated in such combination. 11 ISA-RP12.06.01-2003 Copyright 2003 IS
19、A. All rights reserved. 3.8.1 Entity parameters for intrinsically safe apparatus: C i : Total equivalent internal capacitance of the apparatus that is considered as appearing across the connection facilities of the apparatus. Iior I max : Maximum current (peak a.c. or d.c.) that can be applied to th
20、e connection facilities of the intrinsically safe apparatus circuits without invalidating intrinsic safety. The maximum input current may be different for different terminals. L i : Total equivalent internal inductance of the apparatus that is considered as appearing across the connection facilities
21、 of the apparatus. Li/Ri: The maximum value of ratio of inductance to resistance that is considered as appearing across the terminals of the intrinsically safe apparatus. Pi: Maximum power in an external intrinsically safe circuit that can be applied to the connection facilities of the apparatus. Th
22、e maximum input power may be different for different terminals. Uior Vmax : Maximum voltage (peak a.c. or d.c.) that can be applied to the connection facilities of the apparatus without invalidating the type of protection. The maximum input voltage may be different for different terminals. 3.8.2 Ent
23、ity parameters for associated apparatus: Coor Ca : Maximum capacitance in an intrinsically safe circuit that can be connected to the connection facilities of the apparatus. Io. or I sc : Maximum current (peak a.c. or d.c.) in an intrinsically safe circuit that can be taken from the connection facili
24、ties of the apparatus. Loor L a : Maximum inductance in an intrinsically safe circuit that can be connected to the connection facilities of the apparatus. Lo/Roor La/Ra: The maximum value of ratio of inductance to resistance that may be connected to the intrinsically safe circuit of the associated a
25、pparatus. Po : Maximum electrical power in an intrinsically safe circuit that can be taken from the apparatus. Uoor Voc : Maximum output voltage (peak a.c. or d.c.) in an intrinsically safe circuit that can appear under open-circuit conditions at the connection facilities of the apparatus. 3.8.3 Add
26、itional entity parameters for associated apparatus with multiple channels may include the following: I t : The maximum DC or peak AC current that can be drawn from any combination of terminals of a multiple-channel associated apparatus configuration. Vt : The maximum DC or peak AC open circuit volta
27、ge that can appear across any combination of terminals of a multiple-channel associated apparatus configuration. 3.9 galvanic isolation: the transfer of electrical power or signal from one circuit to another by means that do not include a direct electrical connection (e.g., through an isolating tran
28、sformer or optical coupler). ISA-RP12.06.01-2003 12 Copyright 2003 ISA. All rights reserved. 3.10 hazardous (classified) location: a location in which fire or explosion hazards may exist due to flammable gases or vapors, flammable liquids, combustible dust, or ignitable fibers or flyings. 3.11 ident
29、ified: Identified (as applied to equipment). Recognizable as suitable for the specific purpose, function, use, environment, application, and so forth, where described in a particular Code requirement. FPN: Some examples of ways to determine suitability of equipment for a specific purpose, environmen
30、t, or application include investigations by a qualified testing laboratory (listing and labeling), an inspection agency, or other organizations concerned with product evaluation. 3.12 intrinsic safety: a type of protection in which a portion of the electrical system contains only intrinsically safe
31、equipment (apparatus, circuits, and wiring) that is incapable of causing ignition in the surrounding atmosphere. No single device or wiring is intrinsically safe by itself (except for battery-operated, self-contained apparatus such as portable pagers, transceivers, gas detectors, etc., which are spe
32、cifically designed as intrinsically safe, self-contained devices), but is intrinsically safe only when employed in a properly designed intrinsically safe system. Also see “associated apparatus.“ 3.13 intrinsic safety barrier: a network designed to limit the energy (voltage and current) available to
33、the protected circuit in the hazardous (classified) location, under specified fault conditions (see ISA 12.01.01). 3.14 intrinsic safety ground system: a grounding system that has a dedicated conductor isolated from the power system, except at one point, so that ground currents will not normally flo
34、w, and that is reliably connected to a grounding electrode in accordance with Article 250 of the NEC . 3.15 intrinsically safe apparatus: Intrinsically Safe Apparatus: Apparatus in which all the circuits are intrinsically safe. 3.16 intrinsically safe circuit: Intrinsically Safe Circuit: A circuit i
35、n which any spark or thermal effect is incapable of causing ignition of a mixture of flammable or combustible material in air under prescribed test conditions. FPN: Test conditions are described in ANSI/UL 913-1997 Standard for Safety, Intrinsically Safe Apparatus and Associated Apparatus for Use in
36、 Class I, II, and III, Division 1, Hazardous (Classified) Locations. 13 ISA-RP12.06.01-2003 Copyright 2003 ISA. All rights reserved. 3.17 intrinsically safe systems: Intrinsically Safe System: An assembly of interconnected intrinsically safe apparatus, associated apparatus, and interconnecting cable
37、s in that those parts of the system that may be used in hazardous (classified) locations are intrinsically safe circuits. FPN: An intrinsically safe system may include more than one intrinsically safe circuit. 3.18 labeled: equipment or materials to which has been attached a label, symbol, or other
38、identifying mark of an organization that is acceptable to the authority having jurisdiction and concerned with product evaluation, that maintains periodic inspection of production of labeled equipment or materials, and by whose labeling the manufacturer indicates compliance with appropriate standard
39、s or performance in a specified manner (for additional information, see NEC Article 100). 3.19 listed: equipment, materials or services included in a list published by an organization acceptable to the authority having jurisdiction and concerned with evaluation of products or services, that maintain
40、s periodic inspection of production of listed equipment or materials or periodic evaluation of services, and whose listing states that the equipment, material or services either meets appropriate designated standards or has been tested and found suitable for a specified purpose. (See NEC Article 100
41、.) 3.20 qualified person: one who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training on the hazards involved. 3.21 simple apparatus: Simple Apparatus. An electrical component or combination of components o
42、f simple construction with well-defined electrical parameters which does not generate more than 1.5 volt, 100 milliamps and 25 milliwatts, or a passive component which does not dissipate more than 1.3 watts and which is compatible with the intrinsic safety of the circuit in which it is used. FPN: Th
43、e following apparatus are examples of simple apparatus: a) Passive components, for example switches, junction boxes, resistance temperature devices and simple semiconductor devices such as LEDs; b) Sources of generated energy, for example thermocouples and photocells, which do not generate more than
44、 1.5 V, 100 mA and 25 mW. ISA-RP12.06.01-2003 14 Copyright 2003 ISA. All rights reserved. 3.22 unclassified locations Unclassified Location: Locations determined to be neither Class I, Division 1; Class I, Division 2; Class I, Zone 0; Class I, Zone 1; Class I, Zone 2; Class II, Division 1; Class II,
45、 Division 2; Class III, Division 1; Class III, Division 2; or any combination thereof. 3.23 wiring drawing: a drawing or other document created by the user based upon the relevant control drawings. The wiring drawing is used by the installer to determine the type, color, and size of the wire used to
46、 connect each terminal of the equipment used in the intrinsically safe circuit. 4 Article 504 and 505 of the NEC (ANSI/NFPA 70-2002) with explanation 504.1 Scope. This article covers the installation of intrinsically safe (I.S.) apparatus, wiring, and systems for Class I, II, and III locations. 504.
47、2 Definitions. Associated Apparatus: Apparatus in which the circuits are not necessarily intrinsically safe themselves, but that affect the energy in the intrinsically safe circuits and are relied on to maintain intrinsic safety. Associated apparatus may be either of the following: Intrinsic safety
48、barriers are a common form of associated apparatus. These barriers are connected between the intrinsically safe apparatus and the control equipment. Their primary purpose is to limit the energy to the hazardous location under fault conditions. They may also provide isolation, signal conditioning, or
49、 both. There are also many types of associated apparatus that normally are not referred to as intrinsic safety barriers, but have energy-limiting circuits suitable for connection directly to intrinsically safe apparatus. An example of this type of associated apparatus is a controller that is not itself intrinsically safe, but has connections for intrinsically safe sensors. 504.3 Application of Other Articles. Except as modified by this article, all applicable articles of this Code shall apply. Although intrinsically safe circ
