NFPA 70E

National Fire Protection Association 70E, standard for electrical safety in the workplace is a consensus standard approved as an American national standard. Whereas the NFPA 70 National Electrical Code is primarily an installation standard for premise electrical systems, focuses on electrical safety requirements to protect individuals working on or near electrical equipment. This article will discuss some of the key aspects of the 2004 Edition of NFPA 70E, with a focus on safety-related work practices. In addition, this article also presents some of the potential directions for requirements in future editions of NFPA 70E.     

NFPA 110 and its impact on transfer switching of emergency andstandby power

A review of National Fire Protection Association (NFPA) 110, a standard for emergency and standby power systems, is presented with particular emphasis on transfer switching. NFPA 110 goes beyond the National Electrical Code in stipulating coordinated installation, maintenance and operational and testing requirements. It is shown how this standard is now leading to safer and more reliable emergency and standby power installations     

Safety practices in electrolytic cell line working zones: 1994changes

In 1974 the Electrical Cell Line Working Group of the Chemical Industry Committee prepared a trial-use standard for Electrical Safety Practices in Electrolytic Cell Line Working Zones. Comments on the trial-use standard were incorporated into a full-status standard and published as IEEE Std 463-1977, IEEE Standard for Electrical Safety Practices in Electrolytic Cell Line Working Zones. IEEE Std 463-1977 was reaffirmed in 1987. IEEE Std 463 was used as a source document for Article 668, Electrolytic Cells, of the National Electrical Code (ANSI/NFPA 70); Part 1, Chapter 4H, Specific Purpose Equipment and Installations-Electrolytic Cells of the Standard for Electrical Safety Requirements for Employee Work Places (NFPA 70B-1988); and OSHA 1910.306(h), Electrolytic Cells. In 1991 a working group was formed to review and update IEEE Std 463. The purpose of this article is to describe the current update to IEEE Std 463. The current application of IEEE Std 463 in relation to NFPA 70; NFPA 70E, Parts 1 and 2; and OSHA 1910 Subpart S-Electrical are discussed     

Hazard/risk evaluation - What is it?

Many have struggled with how to address the requirement for an evaluation contained in the National Fire Protection Association (NFPA) 70E [1]. Many believe that risk management meets this requirement. This article will provide a definition for what a hazard/risk evaluation is and a method for performing a hazard/risk evaluation. The risk assessment and how it fits in an overall risk management process and the relationship between risk assessment and hazard/risk evaluation are also discussed. The flowchart currently in NFPA 70E does not start with the right question and needs modification. This article will explore a new starting place for the thought process and suggest that the flowchart in NFPA 70E needs modification.     

Important nonIEEE standards

This paper presents a brief overview of the scope and revision of standards outside IEEE that are very important to our society. The National Fire Protection Association (NFPA) sponsors standards NFPA 70, 70B, and 70E and various other standards. Our Society has formal relationships (liaisons) to the technical committees that revise these standards through the Standards Association-Standards Coordinating Committee (SCC) 18. SCC 18 reviews and coordinates the recommendations of IEEE technical committees to establish the IEEE consensus position for the voting members on NFPA technical committees and code making panels.     

NFPA 70E 2000: updating electrical safety requirements for employeeworkplaces

The authors describe NFPA 70E, which is intended primarily for those who commission, start up, operate and maintain electrical systems and equipment. Safe condition of electrical facilities and equipment is best achieved by adherence to NFPA 70, the National Electrical Code, during the design, procurement, and installation phases of such equipment. Following the policies, principles, practices and procedures advocated by NEPA, 70E provides a reasonable and effective approach to the safe conduct of electrical work by employees in the workplace     

常压流化床锅炉预防燃烧事故标准（一）

常压流化床锅炉预防燃烧事故标准（一）ＳｔａｎｄａｒｄｆｏｒＰｒｅｖｅｎｔｉｏｎｏｆＣｏｍｂｕｓｔｉｏｎＨａｚａｒｄｓｉｎＡｔｍｏｓｐｈｅｒｉｃＦｌｕｉｄｉｚｅｄＢｅｄＣｏｍｂｕｓｔｉｏｎＳｙｓｔｅｍＢｏｉｌｅｒｓ￥ＪｉｎｇＹｉ－ｄａｏ；ＹｕＬｉｎｇ；...     

常压流化床锅炉预防燃烧事故标准（续）

常压流化床锅炉预防燃烧事故标准（续）ＳｔａｎｄａｒｄｆｏｒＰｒｅｖｅｎｔｉｏｎｏｆＣｏｍｂｕｓｔｉｏｎＨａｚａｒｄｓｉｎＡｔｍｏｓｐｈｅｒｉｃＦｌｕｉｄｉｚｅｄＢｅｄＣｏｍｂｕｓｔｉｏｎＳｙｓｔｅｍＢｏｉｌｅｒｓ￥ＪｉａｎｇＹｉ－ｄａｏｅｔｃ．Ａｂｓ...     

Training and qualifying your employees

Procedures alone cannot provide an improvement in electrical safety performance. Personnel who are exposed to electrical hazards must understand the basics of electrical hazards and safe work practices in order to implement the procedures. Training and qualifying your employees on these issues can be difficult and confusing. This article outlines a process for training employees on electrical safety issues. It will define "qualified" in terms that will satisfy the requirements of the Occupational Safety and Health Administration (OSHA) and NFPA 70E of the National Fire Protection Agency (NFPA) and also define the steps to meet the requirements of being qualified. The information contained in this article is the result of training the author has performed with electricians and nonelectrical personnel. The information is based upon the interpretation of the author. Employers should review the information and compare it to their interpretation of the regulations.     

Comparisons of the IEC and NFPA/ANSI Electrical Standards for Industrial Machines and Equipment

The International Electrotechnical Commission (IEC) has issued the second edition of Publication 204-1, Electrical Equipment for Industrial Machines. The National Fire Protection Association (NFPA) Committee 79 recently completed its work on the 1984 edition of the Electrical Standard for Industrial Machinery, covering metalworking machine tools, plastics machinery, and mass production industrial equipment. This standard is slated to replace the now dated Joint Industrial Council (JIC) electrical and electronic standards. These two publications will become the predominant standards relating to safety from electrical shock and fire in electrical equipment for industrial machines. Their basic aspects are described and comparisons between the major areas of these publications are drawn.     

中美外部雷电防护系统设计规范比较

从风险评估、防雷系统的材料、接闪器、引下线、接地体等几个方面,介绍了NFPA780—2011外部防雷的相关技术要求,并与中国防雷设计规范的要求进行比较,为海外设计项目提供了设计参考。     

IR sightglasses protect against arc-flash exposure

The intense energy and duration of an electric arc flash represents a very unique exposure. Everyday work clothes made from regular cotton or polyester cotton blended fabrics, regardless of weight, can be readily ignited at some exposure level. Once ignited, the clothing will continue to burn, adding to the extent of the injury sustained from the arc alone. The National Fire Protection Association (NFPA 70E) standard for electrical safety requirements for employee workplaces now requires employees to wear flame-resistant (FR) protective clothing wherever there is possible exposure to an electric arc flash. This clothing must meet the requirements of ASTM International, formally known as the American Society for Testingand Materials (ASTM) document reference F1506. It also requires employers to perform a flash hazard analysis to determine the flash protection boundary distance.     

Electrical arcing phenomena: a historical perspective and comparative study of the standards: IEEE 1584 and NFPA 70 E

The exposure to hazards associated with electrical arcing phenomena when working on energized equipment is a topic of significant interest to industrial plant personnel. This article provides an overview of the current arc-flash standards, focusing on the methods used to calculate incident energy levels in a system. A thorough sensitivity analysis of the arc-flash hazard incident energy calculations currently adopted by the IEEE 1584 standard leads to some possible conservative simplification of the equations. These simple equations could be used for a quick first-cut assessment of the incident energy levels present in a system. A case study using data from a typical petrochemical application provides a comparison of the National Fire Protection Association (NFPA) 70E and IEEE 1584 arc-flash incident energy equations and the results obtained using the proposed simplified calculations.     

对《半导体少长针消雷器的实效不容否定》一文的两点意见

在美国消雷器普经一度是美国大气科学院,闪电专家和防雷专家讨论会上的主要议题,但消雷概念在会上完全被否定。美国防火协会防雷法规委员会曾全体投票一致拒绝将美国消雷器列入防雷法规。     

Grounding for Emergency and Standby Power Systems

The basic functions of system and equipment grounding is presented, fundamental grounding requirements for service-supplied and separately derived power systems which operate at 600 V or less are discussed. Several grounding arrangements for alternate power supplies are also discussed and graphically illustrated. The grounding requirements are primarily derived from the National Electrical Code, NFPA No. 70-1978. The paper is intended to be the basis for a new chapter on grounding in the next edition of IEEE Standard 446-1974, Recommended Practice for Emergency and Standby Power Systems.     

Surface Temperature Test Methods Per IEEE 1349

The fine print note (FPN) No. 1 in 2005 National Electrical Code (NEC) Article 501.8 (B) [ANSI/NFPA 70, National Electrical Code, 2005 (NEC)] cautions users to "consider the temperature of internal and external surfaces that may be exposed to the flammable atmosphere" when putting a motor into service in a Class I, Division 2 environment. Thus, it is critical that manufacturers and users of industrial electric motors understand that internal peak temperatures exceed the external peak temperatures. This paper presents three common IEEE 1349 [IEEE 1349-2001, IEEE Guide for the Application of Electric Motors in Class I, Division 2 Hazardous (Classified) Locations] test methods used by manufacturers to determine these internal peak temperatures. Potential test method error and the test results from the three test methods are also presented. IEEE 1349 provides only guidance when performing these test methods so this paper intends to provide additional clarification. The test motors presented in this paper are low voltage, ac induction, severe-duty, energy-efficient, totally enclosed fan-cooled motors commonly used in the "Petrochemical Industry."     

Electrical Area Classification drawings: a comparison

This article compares the types of Electrical Area Classification drawings that have been prepared for chemical and petroleum processes and highlights the differences and, in particular, the application variations of NFPA 497A and API RP500. It discusses the complexities in applying these standards. Finally, it presents a technique that meets OSHA Process Safety Management requirements and has other significant advantages     

NFPA12标准下水电站发电机CO2灭火管路设计探讨

主要讨论了NFPA12标准下水电站发电机CO2灭火与国标水喷雾灭火方式的优缺点对比,以及发电机CO2灭火管路设计计算。随着社会和科技的发展,中国水电站会逐步实现无人值班,发电机灭火也会由水喷雾灭火为主,逐步改变为CO2灭火为主。     

Intrinsically Safe Systems?Trends in Design and Installation Standards

Intrinsic safety is a mature proven method to achieve a safe installation of electrical apparatus in a location made hazardous by the presence of flammable or combustible materials. Standards for intrinsically safe apparatus are still evolving. Underwriters' Laboratories, Inc. Standard 913-1975 and NFPA 493-1975 are the most c?omplete statement of requirements for intrinsically safe apparatus and systems yet published. The forthcoming Instrument Society of America Recommended Practice on installation of intrinsically safe systems will fill a pressing need for an installation guide. The National Electrical Code is also changing to recognize the needs of those in the process industries who use intrinsically safe systems and similar apparatus. Much yet needs to be done to define design constraints and Construction requirements for intrinsically safe apparatus. This work is underway.     

锅炉炉膛瞬态防爆设计压力的取值

锅炉炉膛防爆压力的选取近年来在锅炉招标中经常讨论和引起争议。通过对美国NFPA85标准相关条文的分析,对国内锅炉制造厂在设计刚性梁时2种不同方法的对比,并对采用控制手段对锅炉炉膛进行保护的具体措施的说明,以及发生炉膛内爆的可能性分析和引风机的不同形式对炉膛负压的影响,得出将炉膛的瞬态防爆压力不必提高到±8.7 kPa以上的结论。