1、NEMA Standards PublicationNational Electrical Manufacturers AssociationNEMA SG 10-2013Guide to OSHA and NFPA 70E Safety Requirements When Servicing and Maintaining Medium-Voltage Switchgear, Circuit Breakers, and Medium-Voltage Controllers Rated above 1000 VNEMA Standards Publication SG 10-2013 Guid
2、e to OSHA and NFPA 70E Safety Requirements When Servicing and Maintaining Medium-Voltage Switchgear, Circuit Breakers, and Medium-Voltage Controllers Rated above 1000 V Published by: National Electrical Manufacturers Association 1300 North 17th Street, Suite 900 Rosslyn, Virginia 22209 www.nema.org
3、2013 National Electrical Manufacturers Association. All rights, including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literacy and Artistic Works, and the International and Pan American copyright conventions. 2013 Na
4、tional Electrical Manufacturers Association NOTICE AND DISCLAIMER The information in this publication was considered technically sound by the consensus of persons engaged in the development and approval of the document at the time it was developed. Consensus does not necessarily mean that there is u
5、nanimous agreement among every person participating in the development of this document. NEMA standards and guideline publications, of which the document contained herein is one, are developed through a voluntary consensus standards development process. This process brings together volunteers and/or
6、 seeks out the views of persons who have an interest in the topic covered by this publication. While NEMA administers the process and establishes rules to promote fairness in the development of consensus, it does not write the document and it does not independently test, evaluate, or verify the accu
7、racy or completeness of any information or the soundness of any judgments contained in its standards and guideline publications. NEMA disclaims liability for any personal injury, property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly
8、or indirectly resulting from the publication, use of, application, or reliance on this document. NEMA disclaims and makes no guaranty or warranty, express or implied, as to the accuracy or completeness of any information published herein, and disclaims and makes no warranty that the information in t
9、his document will fulfill any of your particular purposes or needs. NEMA does not undertake to guarantee the performance of any individual manufacturer or sellers products or services by virtue of this standard or guide. In publishing and making this document available, NEMA is not undertaking to re
10、nder professional or other services for or on behalf of any person or entity, nor is NEMA undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent pro
11、fessional in determining the exercise of reasonable care in any given circumstances. Information and other standards on the topic covered by this publication may be available from other sources, which the user may wish to consult for additional views or information not covered by this publication. N
12、EMA has no power, nor does it undertake to police or enforce compliance with the contents of this document. NEMA does not certify, test, or inspect products, designs, or installations for safety or health purposes. Any certification or other statement of compliance with any health- or safety-related
13、 information in this document shall not be attributable to NEMA and is solely the responsibility of the certifier or maker of the statement. NEMA SG 10-2013 Page i 2013 National Electrical Manufacturers Association Foreword This guide was written to emphasize basic principles and guidance for safety
14、 when performing inspection, operation, and maintenance of medium-voltage switchgear, circuit breakers, and medium-voltage controllers rated above 1000 V. It also draws the readers attention to important OSHA and NFPA safety standards. Proposed or recommended revisions should be submitted to: Vice P
15、resident, Technical Services National Electrical Manufacturers Association 1300 North 17th Street, Suite 900 Rosslyn, VA 22209 This guide was developed by the Switchgear Section of the Power Equipment Division. Section approval of the guide does not necessarily imply that all section members voted f
16、or its approval or participated in its development. At the time this guide was approved, the Section was composed of the following members: ALSTOM Grid Inc.Charleroi, PA Cooper Power SystemsWaukesha, WI Eaton Inc.Pittsburgh, PA Federal PacificBristol, VA General Electric Co.Plainville, CT Hubbell Po
17、wer SystemsColumbia, SC Schneider ElectricSmyrna, TN S personal protective equipment; including arc-flash suit; insulating and shielding materials; and insulated tools and test equipment. A person can be considered qualified with respect to certain equipment and methods but still be unqualified for
18、others.” 2.2 APPROACH BOUNDARIES Refer to NFPA 70E Article 130.4 for specific requirements regarding distances from exposed energized electrical conductors and circuit parts that define approach boundaries. NEMA SG 10-2013 Page 6 2013 National Electrical Manufacturers Association Section 3 TRAINING
19、In accordance with 29 CFR 1910.332 and NFPA 70E Chapter 1, all personnel associated with maintenance or service of switchgear assemblies should be qualified. They should be trained in: a) Safety-related work practices and procedural requirements necessary to provide protection from electrical hazard
20、s b) The ability to identify and understand the relationship between electrical hazards and possible injury. c) The skill and techniques necessary to distinguish exposed energized parts from other parts of electrical equipment. d) The skills and techniques necessary to determine the nominal voltage
21、of exposed energized parts. e) Approach distances specified in 29 CFR 1910.333 and the flash protection boundary specified in NFPA 70E Chapter 1. f) Decision-making process necessary to determine the extent of the hazard and the personal protective equipment and job planning necessary to perform the
22、 task safely. Qualified persons should also be trained in and familiar with: a) Lockout/tagout procedures specified in 29 CFR 1910.147 and NFPA 70E Article 120.2. b) Proper use of and maintenance of personal protective equipment as specified in NFPA 70E Article 130.7. c) Proper use of test equipment
23、. d) Proper procedures to apply temporary protective grounds. e) Electrical equipment in general, as well as the particular model of equipment involved. NEMA SG 10-2013 Page 7 2013 National Electrical Manufacturers Association Section 4 JOB PLAN 4.1 JOB PLAN CREATION Before servicing, maintaining, o
24、r performing diagnostic routines on switchgear assemblies, a job plan in accordance with NFPA 70E Chapter 1 is required. See Appendix A for an example. Established standards and regulations related to maintenance, operation, installation, and safety, including OSHA requirements, National Electric Sa
25、fety Code (ANSI C2), National Electric Code (NFPA 70), Recommended Practices for Electrical Equipment Maintenance (NFPA 70B), and Standard for Electrical Safety in the Workplace (NFPA 70E) should be available, closely studied, and followed. 4.2 JOB BRIEFING The person in charge of servicing, maintai
26、ning, or diagnostic routines on switchgear assemblies should be qualified and responsible in accordance with NFPA 70E. That person should conduct a job briefing with all employees involved at the beginning of each day and each shift, and audit practices to assure conformance. The job briefing should
27、 include, but is not limited to: a) Tasks and objectives b) Electrical system parameters c) Voltages (line-to-line) d) Short-circuit current available at equipment e) Power sources and protective device(s) fault clearing time f) System single-line or three-line electrical diagrams g) Approach bounda
28、ries per NFPA 70E Chapter 1 h) All sources of power, including back feed sources (see note below) i) Hazards j) Work procedures k) Energy source controls l) Personal protective equipment m) Testing and service equipment n) Safety grounding equipment o) Lockout and tagout procedures and materials p)
29、Switchgear assembly information, including modifications after installation q) Manufacturers instruction books, recommended practices, and checklists r) Manufacturers outline, schematic and detail wiring drawings, including modifications after installation s) Nameplate data and information t) Review
30、 local safety procedures with responsible persons u) Review and understand consequences of actions (and failure to act) on other operations at facility NOTE“Back feed” refers to any possible source of energization of conductors from other than the normal source. This can include sources such as test
31、 equipment, generators, alternate sources, emergency sources, temporary connections, and many other sources of voltage (intentional or unintentional). Special precautions should be taken to isolate control and instrument transformers from their primary circuits prior to injection of any secondary te
32、st voltage. NEMA SG 10-2013 Page 8 2013 National Electrical Manufacturers Association Section 5 EMERGENCY PLAN Emergency plans include the following items as a minimum: a) Communications. b) First aid per 29 CFR 1910.151. c) CPR per 29 CFR 1910.269(b)(1). d) Medical services availability and evacuat
33、ion plan per 29 CFR 1910-38(c)(2) and 29 CFR 1926 Subpart C. NEMA SG 10-2013 Page 9 2013 National Electrical Manufacturers Association Section 6 AREA SECURITY Barricades (tapes, cones, fences, or metal structures) should be erected in the work area to provide warning and to limit access to a hazardo
34、us area. Refer to 29 CFR 1910.335 and NFPA 70E Chapter 1. NEMA SG 10-2013 Page 10 2013 National Electrical Manufacturers Association Section 7 REMOVING EQUIPMENT FROM SERVICE The individuals correct sequence of actions while performing service or maintenance is essential to prevent accidents. Each p
35、ersons knowledge, mental awareness, and planned and executed actions often determine whether an accident will occur. Incorrect procedures, unplanned energization from potential sources of back feed, and/or equipment malfunctions, among other reasons, are causes of accidents around electrical equipme
36、nt. Only a qualified person should be allowed to de-energize equipment and remove it from service. The following summarizes typical safety practices, including those required by OSHA and NFPA: a) Assume all conductors are energized unless properly grounded. b) Wear proper personal protective equipme
37、nt. c) Disconnect all primary sources of electrical power. d) Disconnect all control power sources. e) Isolate voltage transformers and control power transformers at the primary and secondary connections. f) Lockout/tagout all sources of energy, including control power. g) Test for absence of voltag
38、e using a testing device intended for the voltage. See Section 7.1. h) Interlocks, position indicators, and visual inspection alone do not guarantee personal safety. i) Apply temporary protective grounds in accordance with Section 7.2. j) Have another qualified person conduct a safety check to ensur
39、e circuits are de-energized, tagged out/locked out, and properly grounded. 7.1 VOLTAGE DETECTION Voltage detection should be performed only by a qualified person who is properly trained in accordance with 29 CFR 1910.333(b) (2) (iv) (B) and NFPA 70E Chapter 1. The procedure below summarizes typical
40、safety practices used when de-energizing circuits or equipment, including those required by OSHA and NFPA. 1) Test voltage detector operation against known voltage source (at the same voltage as the operating voltage of the circuit to be tested). 2) Test circuit to be serviced or grounded for absenc
41、e of voltage. 3) Retest voltage detector operation against known voltage source (at the same voltage as the operating voltage of the circuit tested) to verify that the voltage detector has not failed. Some equipment might have a built-in voltage detection system. This can be used provided the system
42、 can be tested to prove that it is in working condition. Follow items 1-3 above. 7.2 GROUNDING Temporary protective grounding equipment should be applied. Refer to 29 CFR 1910.269. The grounding conductors and connections should be in good condition and adequate to carry full fault current from all
43、possible sources for the maximum duration required for the protective equipment to clear the circuit. Refer to NFPA 70E Chapter 1. Some equipment might have built-in grounding switches. These can be used with, or in place of, temporary protective grounds. NEMA SG 10-2013 Page 11 2013 National Electr
44、ical Manufacturers Association 7.3 LOCKOUT/TAGOUT PROCEDURES Tags, by themselves, are not adequate to ensure that a circuit will remain de-energized. Lockout/tagout requirements are found in 29 CFR 1910.147 and 1910.333, and NFPA 70E Article 120. NEMA SG 10-2013 Page 12 2013 National Electrical Manu
45、facturers Association Section 8 RETURNING EQUIPMENT TO SERVICE Only a qualified person should be allowed to re-energize equipment and return it to service. The following points summarize typical safety practices, including those required by OSHA and NFPA: a) Inspect equipment for tools, loose wires,
46、 test jumpers, temporary protective grounds, etc. b) Test as required (e.g., power frequency withstand voltage test, megger). c) Inform facility personnel of pending equipment energization. d) Follow manufacturers instructions. e) Clear area of personnel. f) Wear proper personal protective equipment
47、. g) Remove temporary protective grounds or open grounding switches. h) Remove lockout tags and locks. i) Energize control circuits. j) Secure all doors, covers, latches, and other points of access. k) Restore equipment to operating configuration. NEMA SG 10-2013 Page 13 2013 National Electrical Man
48、ufacturers Association Section 9 Recordkeeping and Responsibilities of Individuals 9.1 RECORDKEEPING All field testing records, including replacement of parts, repairs, equipment maintenance and inspection records, and personnel training records must be maintained. 9.2 RESPONSIBILITIES OF INDIVIDUAL
49、S It is the responsibility of all levels in the organization, from management to members of the workforce, to ensure a safe workplace where the level of risk from electrical hazards that might cause injury, illness, or death is as low as reasonably achievable. Managers shall expect all personnel to comply with these regulations. Members of the workforce are expected to report immediately to management any unsafe conditions and stop work until the condition is corrected. Field supervision while the work is performed should be assigned to a qualified person
