1、 TIA-4950-A (Revision of TIA-4950) May 2014Requirements for Battery-Powered, Portable Land Mobile Radio Applications in Class I, II, and III, Division 1, Hazardous (Classified) Locations ANSI/TIA-4950-A-2014 APPROVED: MAY 13, 2014 NOTICE TIA Engineering Standards and Publications are designed to ser
2、ve the public interest through eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for their particular need. The existence of suc
3、h Standards and Publications shall not in any respect preclude any member or non-member of TIA from manufacturing or selling products not conforming to such Standards and Publications. Neither shall the existence of such Standards and Publications preclude their voluntary use by Non-TIA members, eit
4、her domestically or internationally. Standards and Publications are adopted by TIA in accordance with the American National Standards Institute (ANSI) patent policy. By such action, TIA does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting
5、the Standard or Publication. This Standard does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the responsibility of the user of this Standard to establish appropriate safety and health practices and to determine the applicability
6、of regulatory limitations before its use. (From Project No. ANSI/TIA-PN-4950-A, formulated under the cognizance of the TIA TR-8 Mobile and Personal Private Radio Standards, TR-8.21 Subcommittee on Land Mobile Radio (LMR) Intrinsic Safety (IS) Consideration). Published by TELECOMMUNICATIONS INDUSTRY
7、ASSOCIATION Technology (b) there is no assurance that the Document will be approved by any Committee of TIA or any other body in its present or any other form; (c) the Document may be amended, modified or changed in the standards development or any editing process. The use or practice of contents of
8、 this Document may involve the use of intellectual property rights (“IPR”), including pending or issued patents, or copyrights, owned by one or more parties. TIA makes no search or investigation for IPR. When IPR consisting of patents and published pending patent applications are claimed and called
9、to TIAs attention, a statement from the holder thereof is requested, all in accordance with the Manual. TIA takes no position with reference to, and disclaims any obligation to investigate or inquire into, the scope or validity of any claims of IPR. TIA will neither be a party to discussions of any
10、licensing terms or conditions, which are instead left to the parties involved, nor will TIA opine or judge whether proposed licensing terms or conditions are reasonable or non-discriminatory. TIA does not warrant or represent that procedures or practices suggested or provided in the Manual have been
11、 complied with as respects the Document or its contents. If the Document contains one or more Normative References to a document published by another organization (“other SSO”) engaged in the formulation, development or publication of standards (whether designated as a standard, specification, recom
12、mendation or otherwise), whether such reference consists of mandatory, alternate or optional elements (as defined in the TIA Engineering Manual, 4thedition) then (i) TIA disclaims any duty or obligation to search or investigate the records of any other SSO for IPR or letters of assurance relating to
13、 any such Normative Reference; (ii) TIAs policy of encouragement of voluntary disclosure (see Engineering Manual Section 6.5.1) of Essential Patent(s) and published pending patent applications shall apply; and (iii) Information as to claims of IPR in the records or publications of the other SSO shal
14、l not constitute identification to TIA of a claim of Essential Patent(s) or published pending patent applications. TIA does not enforce or monitor compliance with the contents of the Document. TIA does not certify, inspect, test or otherwise investigate products, designs or services or any claims of
15、 compliance with the contents of the Document. ALL WARRANTIES, EXPRESS OR IMPLIED, ARE DISCLAIMED, INCLUDING WITHOUT LIMITATION, ANY AND ALL WARRANTIES CONCERNING THE ACCURACY OF THE CONTENTS, ITS FITNESS OR APPROPRIATENESS FOR A PARTICULAR PURPOSE OR USE, ITS MERCHANTABILITY AND ITS NONINFRINGEMENT
16、 OF ANY THIRD PARTYS INTELLECTUAL PROPERTY RIGHTS. TIA EXPRESSLY DISCLAIMS ANY AND ALL RESPONSIBILITIES FOR THE ACCURACY OF THE CONTENTS AND MAKES NO REPRESENTATIONS OR WARRANTIES REGARDING THE CONTENTS COMPLIANCE WITH ANY APPLICABLE STATUTE, RULE OR REGULATION, OR THE SAFETY OR HEALTH EFFECTS OF TH
17、E CONTENTS OR ANY PRODUCT OR SERVICE REFERRED TO IN THE DOCUMENT OR PRODUCED OR RENDERED TO COMPLY WITH THE CONTENTS. TIA SHALL NOT BE LIABLE FOR ANY AND ALL DAMAGES, DIRECT OR INDIRECT, ARISING FROM OR RELATING TO ANY USE OF THE CONTENTS CONTAINED HEREIN, INCLUDING WITHOUT LIMITATION ANY AND ALL IN
18、DIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES (INCLUDING DAMAGES FOR LOSS OF BUSINESS, LOSS OF PROFITS, LITIGATION, OR THE LIKE), WHETHER BASED UPON BREACH OF CONTRACT, BREACH OF WARRANTY, TORT (INCLUDING NEGLIGENCE), PRODUCT LIABILITY OR OTHERWISE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
19、DAMAGES. THE FOREGOING NEGATION OF DAMAGES IS A FUNDAMENTAL ELEMENT OF THE USE OF THE CONTENTS HEREOF, AND THESE CONTENTS WOULD NOT BE PUBLISHED BY TIA WITHOUT SUCH LIMITATIONS. ANSI/TIA-4950-A i Foreword (This foreword is not part of this standard.) This document is being published in the interest
20、of an urgent need for technical information on operation of Land Mobile Radio products in Class I, II, and III Division 1 Hazardous (classified) Locations. This document was developed by the Land Mobile Radio Intrinsic Safety Considerations subcommittee (TR-8.21). This document is being published to
21、 address the need for technical information related to the design, manufacturing, and testing of battery-powered, Land Mobile Radios (LMR) equipment, typically either hand-carried or worn on the person, that are designed and manufactured so that they are incapable of being a source of ignition in Di
22、vision 1 Hazardous (Classified) locations as defined in Article 500 of the National Electric Code (NEC) NFPA 70. This Standard relies heavily upon a contribution from Underwriters Laboratories, Inc1. These requirements are based upon sound engineering principles, research, records of tests and field
23、 experience, and an appreciation of the problems of manufacture, installation, and use derived from consultation with and information obtained from manufacturers, users, inspection authorities, and others having specialized experience. They are subject to revision as further experience and investiga
24、tion may show is necessary or desirable. The observance of the requirements of this Standard by a manufacturer is one of the conditions of the continued coverage of the manufacturers product. A product which complies with the text of this Standard will not necessarily be judged to comply with the St
25、andard if, when examined and tested, it is found to have other features which impair the level of safety contemplated by these requirements. A product employing materials or having forms of construction which conflict with specific requirements of the Standard cannot be judged to comply with the Sta
26、ndard. A product employing materials or having forms of construction not addressed by this Standard may be examined and tested according to the intent of the requirements and, if found to meet the intent of this Standard, may be judged to comply with the Standard. Some of the tests or procedures spe
27、cified in this Standard may involve the presence of hazardous voltages and currents or other potential dangers to personnel. Some of these hazards have been identified, and appropriate 1 1997 Underwriters Laboratories Inc. Reprinted with permission. Underwriters Laboratories Inc. Standard For Safety
28、 For Intrinsically Safe Apparatus and Associated Apparatus for Use in Class I, II, and III, Division 1, Hazardous (Classified) Locations, UL 913 Fifth Edition Dated February 21, 1997 ISBN 0-7629-0129-2 ANSI/TIA-4950-A ii warnings have been included in the text TIA Style Manual specifying such tests
29、or procedures. However, appropriate safety precautions are always recommended when performing any laboratory test or procedure. ANSI/TIA-4950-A iii Patent Identification The readers attention is called to the possibility that compliance with this document may require the use of one or more invention
30、s covered by patent rights. By publication of this document no position is taken with respect to the validity of those claims or any patent rights in connection therewith. The following patent holders and patents have been identified in accordance with the TIA intellectual property rights policy: No
31、 patents have been identified. TIA shall not be responsible for identifying patents for which licenses may be required by this document or for conducting inquiries into the legal validity or scope of those patents that are brought to its attention. ANSI/TIA-4950-A iv This page is intentionally blank
32、. ANSI/TIA-4950-A v Table of Contents INTRODUCTION 1 Document Revision History . 1 Normative References . 2 Informative References . 2 1 Scope . 2 2 Purpose . 3 3 Applicability of Other Standards . 3 4 Definitions of Terms, Abbreviations, and acronyms . 4 5 Class I, Zone and Group Equivalency 6 6 Co
33、ntrol Drawing 7 7 Evaluation of Intrinsic Safety 7 7.1 Fundamental requirements . 7 7.2 Evaluation procedure 8 7.3 * Entity evaluation . 9 7.4 * Associated apparatus evaluation . 9 7.5 *Intrinsically safe apparatus inductance and capacitance determination 10 7.6 * Intrinsically safe and associated a
34、pparatus control drawing . 10 7.7 Intrinsically safe apparatus evaluation 11 CONSTRUCTION REQUIREMENTS . 12 8 *Creepage and Clearance Distances 12 9 *Encapsulation 16 10 Field Wiring Connections (deleted in ANSI/TIA-4950-A) . 17 11 Internal Wiring Conductors . 17 12 *Protective Components 17 12.1 Ge
35、neral 17 12.2 Semiconductor Current Limiting (new in ANSI/TIA-4950-A) 17 12.3 Damping windings (deleted in ANSI/TIA-4950-A) 18 12.4 Current-limiting resistors 18 12.5 Blocking capacitors 18 12.6 Shunt protective components 18 12.7 Shunt diode barriers 18 12.8 Optical Isolators . 20 12.9 Piezoelectri
36、c Devices . 20 12.10 Impact test for Piezoelectric Devices . 21 13 Miscellaneous Components 21 13.1 Derating of components . 21 13.2 Plug-In boards and components 21 13.3 * Relays (deleted in ANSI/TIA-4950-A) 21 14 Portable Apparatus Enclosures 21 15 Cells and Batteries . 22 16 *Maximum Temperature
37、. 24 MARKING 25 17 General 25 ANSI/TIA-4950-A vi COMPARISON PROCEDURE FOR DETERMINING SPARK IGNITION CAPABILITY 28 18 * General . 28 18.1 General . 28 18.2 Resistance circuits 28 18.3 Resistance-capacitance circuits 28 19 Maximum voltage and current levels 38 APPARATUS FOR CLASS II AND CLASS III LOC
38、ATIONS 38 20 Applicability of Other Requirements in this Standard 38 21 Specific Requirements for Intrinsic Safety 38 22 * Dust-Tight Enclosures . 39 TEST PROCEDURES 40 23 Protective Transformers Tests (deleted in ANSI/TIA-4950-A) 40 24 Current-Limiting Resistor 40 25 Shunt Diode Protective Barrier
39、Tests . 40 26 Optical Isolator Tests . 41 27 Temperature Tests . 41 28 Small Component Ignition Test. 43 29 Dielectric Tests . 43 30 Mechanical Tests 45 31 Drop Test 45 32 Dust-Tight Enclosure Test . 45 33 Dust Blanketing Temperature Test . 45 34 Lamp Breakage Test (deleted in ANSI/TIA-4950-A) . 46
40、35 Encapsulation Tests 46 35.1 Force test 46 35.2 Impact test . 46 35.3 Solvent vapor exposure . 46 36 Internal Capacitance or Inductance Test . 47 37 Spark Ignition Test . 47 37.1 General Requirements 47 37.2 * Test apparatus 48 37.3 Gas mixtures . 48 38 Verification of Spark Test Apparatus . 50 38
41、.1 General . 50 38.2 Test procedure 51 38.3 Test factors 51 39 Impact Test Procedure for Piezoelectric Devices 52 39.1 Test Procedure 52 ANNEX A (Informative) 53 ANNEX B (Informative) . 63 ANSI/TIA-4950-A vii Table of Figures Figure 18-1 Resistance Circuits 30 Figure 18-2 Resistance Circuits 31 Figu
42、re 18-3 Inductance Circuits 32 Figure 18-4 Inductance Circuits 33 Figure 18-5 Inductance Circuits 34 Figure 18-6 Inductance Circuits 35 Figure 18-7 Capacitance Circuits . 36 Figure 18-8 Capacitance Circuits . 37 Figure 37-1 Test Apparatus for Evaluating Intrinsically Safe Circuits (Measured in Milli
43、amperes . 49 Figure 38-1 Example Control Drawing 56 Table of Tables Table 8-1 Clearances, creepage distances, and distances through casting compound and insulations . 13 Table 16-1 Currents in copper wire 25 Table 29-1 Coated board withstand test values 44 Table 38-1 Current in calibration circuit f
44、or cadmium disc 50 Table 38-2 Current in calibration circuit for tin disc . 50 Table 39-1 Impact Energy 52 Table 39-2 Impact Test Levels . 52 ANSI/TIA-4950-A 1 INTRODUCTION The purpose of this document is to establish product design considerations for an intrinsically safe variation of products that
45、 meet the traditional operating expectations for portable land mobile radios. While the Scope of this standard defines this Standards intended use, users of this standard are encouraged to determine the applicability of this standard to their own particular requirements. This standard shall apply to
46、 battery-powered, portable two-way land mobile equipment certified for use in the United States by either the FCC (for non-Federal government users) or NTIA (for Federal government users), which are to be used in areas designated hazardous (classified) as Class I, Class II, or Class III, Division 1
47、as defined in clause 500.5 of the National Electric Code (NEC). NOTE: Clause 500.8 (B) references use of equipment that has been identified for a Division 1 location as eligible for use in a Division 2 location. Protection against explosion afforded by these specifications is relevant to land mobile
48、 equipment within which the electronics and circuits are incapable of causing an explosion in a surrounding explosive environment. This Standard includes thirty-eight (38) Clauses and two (2) Annexes. Clauses 1 through 38 are normative. Clauses 39 and 40 (Annexes A and B) are informative. Clause 1 p
49、rovides the Scope of this standard, the document revision history, identifies normative and informative references, and provides a listing of terms and acronyms used throughout this Standard. Clauses 2 through 38 integrate UL 913 Revision 5 as part of this standard. Clause 39 (Annex A) provides additional explanatory information to a given clause or sub-clause. An asterisk (i.e. “*”) following a clause or sub-clause number signifies that explanatory material relevant to that clause or sub-clause follows in Annex A. Sections in the document body with asterisks indica
