When you're dealing with industrial and commercial power systems, it's often necessary to pool resources of operational, maintenance, and safety standards. To help fulfill this need, IEEE recently introduced its new Yellow Book.
If you work in an industrial or commercial plant, chances are you need fast answers to maintenance, operation, and/or safety issues every day. You need guidance from an authoritative source, so where should you turn? Several industry guides address such issues including: Recommended Practice for Electrical Equipment Maintenance (NFPB 70B), Standard for Electrical Safety Requirements for Employee Workplaces (NFPB 70E), and the National Electrical Code (NEC). Now, there's a new standard to use as a supplement to these references. The Institute of Electrical and Electronics Engineers, Inc. (IEEE) recently published Std 902-1998, IEEE Guide for Maintenance, Operation, and Safety of Industrial and Commercial Power Systems (IEEE Yellow Book) as a companion to its other color books.
According to its jacket, IEEE Std 902-1998 is a reference for the fundamentals of safe and reliable maintenance and operation of industrial and commercial power systems, regardless of system size or complexity. The book covers maintenance, operation, and safety considerations in system design and also discusses how to develop and use the following:
Maintenance and operations strategy to ensure long-term reliability.
Record keeping and documentation files.
Testing and inspection methods.
Procedures for auditing maintenance and operation performance.
Procedures to ensure safety.
The following Yellow Book chapters, which address safety issues, should help you troubleshoot problems in the industrial and commercial power systems arena.
Chapter 7: Introduction to Electrical Safety. NFPA 70E-1995, Electrical Safety Requirements for Employee Workplaces, defines an electrical hazard as "a dangerous condition, such that, inadvertent or unintentional contact or equipment failure, can result in shock, arc flash burn, thermal burn, or blast." It defines electrical safety as "recognizing hazards associated with the use of electrical energy and taking precautions as that hazards do not cause injury or death."
Why is electrical safety so important? Referring to the table (original article), you can see just how the electrical characteristics of the human body change when exposed to different environments. The figure (on page 54, original article) depicts what amounts of electrical current and voltage affect the human body under these differing conditions. Even the smallest amounts of electrical current and voltage can cause serious harm, therefore, it's critical you institute an electrical safety program.
To understand the NFPA definitions and apply them correctly, you must understand the four main phases of electrical hazard protection:
Design and construct safe electrical installations by complying with the criteria of recognized and generally accepted good engineering practices.
Maintain the integrity of electrical equipment, with particular emphasis on enclosures, insulation, operating mechanisms, grounding, and circuit protective devices.
Unless there are serious overriding circumstances, place electrical equipment in an electrically safe work condition before maintenance personnel work on or near it. You should also use safe practices to establish an electrically safe work condition.
Understand and use safe work practices and adequate protective equipment, tools, and test equipment when it's not feasible to establish an electrically safe work condition, or when de-energizing would create a greater hazard.
Chapter 8: Establishing an Electrical Safety Program. You should practice good electrical safety not only for personal reasons, but also for business, and regulatory/legal concerns. The premise of an electrical safety program is to keep personnel from unnecessary exposure to electrical hazards by either workplace conditions or peoples' actions. The standard lists five major objectives:
To make personnel aware of the rules, responsibilities, and procedures for working safely in an electrical environment.
To demonstrate the employer's intention of fully complying with federal law.
To document general requirements and guidelines for providing workplace facilities free from unauthorized exposure to electrical hazards.
To document general requirements and guidelines directing the activities of personnel, who could be deliberately or accidentally exposed to electrical hazards.
To encourage and make it easier for each employee to be responsible for his or her own electrical safety.
A complete electrical safety program should incorporate directives on management commitment; organizational support; electrical safety policy; electrically safe facilities; documented safe electrical work practices; training and qualification of all personnel; use of protective equipment, tools, and protective methods; use of electrical equipment; documentation; oversight and auditing; technical support; and emergency preparedness.
Chapter 9: Providing and Maintaining Electrically Safe Facilities. Workplace conditions should not be the cause of an electrical shock, burn, or blast; especially for properly designed, installed, and maintained electrical installations. To help you establish an electrically safe workplace, make sure you're familiar with the two major legal documents relating to electrical design, installation, and maintenance requirements in the United States. The first document falls under the authority of the Occupational Safety and Health Administration (OSHA). Of particular importance are 29 CFR 1910, Subpart S (general industry); 29 CFR 1910, Subpart R (special industries); and 29 CFR 1926, Subpart K (construction industry). The second is the NEC, which carries the force of law only when adopted by a governing entity.
Providing safe workplaces begins with the initial design of a facility, process, or piece of equipment. During the installation phase, you should comply with following:
Install equipment in accordance with the operating diagrams, manufacturer's instructions, and other design documents.
Know the NEC requirements.
Neatly install equipment.
Challenge any design information appearing to disagree with the NEC.
After installing new equipment or modifying existing equipment and facilities, you should initiate a safety and fire protection inspection; whether it's required or not. Also, make sure you consider future maintenance in the design of a facility and its electrical equipment. When maintenance requires repairs or replacement parts, remember the potential safety considerations of poor workmanship or "jury-rigged" fixes.
Chapter 10: Safe Electrical Work Practices. Another major objective of an electrical safety program is to establish safe electrical work practices. A significantly greater number of injuries and fatalities are the result of poor or careless practices than poor equipment conditions. Here are some basic rules to follow:
Always assume any electrical circuit conductors, whether bare or insulated, are energized until proven otherwise.
De-energize, lock out, and test all conductors for the absence of voltage before working on or near them.
Only trained, qualified, and authorized personnel should work on or near electrical circuit conductors and circuit parts.
Always use appropriate safety practices, personal protective equipment, tools, and test equipment.
Chapter 11: Protective Equipment, Tools, and Methods. Electrical protective equipment eliminates or reduces hazard severity, the likelihood of an accident given that a hazard exists, and the severity of injury if an accident occurs. Tables 3-3.6 and 3-4.11 of NFPA 70E-1995 summarize the American National Standards Institute (ANSI) and the American Society of Testing and Materials (ASTM) standards pertaining to the selection, care, and use of protective clothing, equipment, and tools.
Chapter 12: Safe Use of Electrical Equipment. The safe use of portable electric tools, temporary extension cords, and testing instruments is dependent on your knowledge of the task and specific equipment used; the integrity of facility grounding and protective systems; and the systems in place to manage inspection and maintenance. People without an in-depth knowledge of the electrical characteristics of the equipment often perform the operation of distribution, utilization, and control equipment. However, they should be knowledgeable of the hazards involved in operating this equipment.
Keep in mind, IEEE standards are not mandatory: Their use is strictly voluntary. Nevertheless, it's good to be aware of all industry standards, specifications, practices, or guides applying to your area of expertise. So if you don't have to use them, why should you? Most of these standards take into account many years of practical experience. This allows you to learn from others' mistakes. Not using nationally recognized standards may lead to legal and monetary problems.
Sidebar: Related Yellow Book Chapters Dealing with Maintenance and Operation
Chapter 1: Overview. Two sentences clearly state the intentions of this standard:
"The objective of this guide is to provide plant engineers with a reference source for the fundamentals of safe and reliable maintenance and operation of industrial and commercial electric power distribution systems."
"The most effective utilization of the information contained in this guide would be its inclusion in a long-term maintenance and operation strategy that is tailored to the individual needs of each power system."
Chapter 2: Operating Diagrams. This guide defines operating diagrams as "road maps" to the operation and maintenance of an industrial or commercial power system. Operating diagrams are items such as vendor drawings and instruction manuals, plant drawings, maintenance histories, spare parts lists, and standard operating procedures. Without these diagrams, anarchy reigns. Keep in mind, consistency is king when it comes to keeping these diagrams readable and understandable.
Chapter 3: System Management. A well-designed and constructed power system will not provide a safe and reliable operation unless you manage it properly. Discussion stresses the fact that you must account for human error in the design, operation, and maintenance of any electrical distribution system; no matter how large or complex. Detailed are load distribution, system integrity, power factor, system protection coordination, and operating economics. A properly managed system usually has relatively few problems, except for forces beyond your control.
Chapter 4: System Control Responsibilities and Clearing Procedures. Despite the skill level of the owner, he or she is ultimately responsible for control of the electrical system. However, everyone who interacts with the power supply and distribution system of an industrial or commercial establishment has some responsibility for the control of that system. This includes maintenance personnel, contractors, and your local utility. Discussion here also centers on the different levels of clearing procedures required for isolating sections within the varying complexities of different electrical distribution systems.
Chapter 5: Maintenance Strategies. NFPA 70B-1998 states "Electrical equipment deterioration is normal, but equipment failure is not inevitable. As soon as you install new equipment, a process of normal deterioration begins. Unchecked, the deterioration process can cause malfunction or an electrical failure." Although most of us agree preventive maintenance is necessary to ensure the reliability of electrical power systems, a wide disparity remains as to the content of a preventive maintenance program. Explained are strategies of proper maintenance and the necessary fundamentals behind those strategies.
Chapter 6: Maintenance Testing Overview. Maintenance testing is an important procedure that can detect deficiencies in electrical equipment before the equipment fails catastrophically. By simulating the various failure modes with nondestructive test methods, you can locate and correct these deficiencies. Described are various nondestructive maintenance tests; however, the standard doesn't include the exact steps. The bibliography lists various testing standards that include instructions to perform the tests.