Nfpa 70 B Chronology Of The Origin And Development 64b7461d2508e

NFPA 70B: Chronology of the origin and development

July 20, 2023
This timeline shows the development for the latest standard over many decades and an outline of topics and practices covered in the code.

The National Fire Protection Agency (NFPA) adopted the Standard for Electrical Equipment Maintenance, 70B in January 2023. The standard has long been around as a recommendation, along with NFPA 70, the National Electric Code and NFPA 70E, the Standard for Electrical Safety in the workplace. The following chronology shows the development for the latest standard over many decades and an outline of topics and practices covered in the code.


An ad hoc committee on electrical equipment maintenance was authorized by NFPA. The National Electric Code committee had received requests to include maintenance recommendations in the National Electric Code, but it was decided NEC was not the proper place and it was handed off to NFPA to determine the need for development of a formal document.

June 27, 1968

NFPA established the Committee on Electrical Equipment Maintenance, with the following scope: “To develop suitable texts relating to preventive maintenance of electrical systems and equipment used in industrial-type applications with the view of reducing loss of life and property. The purpose is to correlate generally applicable procedures for preventive maintenance that have broad application to the more common classes of industrial electrical systems and equipment without duplicating or superseding instruction that manufactures normally provide.”


NFPA 70B-T, Tentative Recommended Practice for Electrical Equipment Maintenance, covered:

  • Why an electrical preventive maintenance program pays dividends;
  • What is an effective preventive maintenance program;
  • Planning and developing an electrical preventive maintenance program.


The Tentative Recommended Practices document was revised to include:

  • A chapter on the fundamentals of electrical equipment maintenance;
  • General maintenance requirements for various types of equipment;
  • A new appendix: How to instruct.


The tentative recommended practice was adopted as NFPA 70B, Recommended Practice for Electrical Equipment Maintenance.


Chapters on electronic equipment, ground-fault protection, wiring devices, and maintenance of electrical equipment subject to long intervals between shutdowns were added. New appendices addressed NEMA plug and receptable configurations and guidelines for long-term maintenance.


Chapters on cable tray systems and on deenergizing and grounding of equipment to provide protection for maintenance personnel were added. An appendix covering equipment storage and maintenance during construction was also added.


This year’s edition added distribution transformers and power transformers.


A chapter on uninterruptible power supply was added.


New chapters were added to cover power system studies, power quality and vibration analysis pertaining to rotating machinery.


This edition rewrote and expanded on the power quality chapter. Maintenance techniques for stationary batteries and infrared inspections were updated and revised. Special handling and disposal consideration were introduced, and employee training was focused to emphasize workplace safety.


The scope of this year’s edition was revised to include preventive maintenance for electronic and communication equipment. A chapter was added for grounding maintenance issues. A new section for gas insulted substation addressed the maintenance issues resulting from regulatory changes in the electrical utility industry. The chapter on power quality was enhanced with information on the latest technology on voltage fluctuation. A new annex suggested maintenance intervals for electrical equipment.


A new chapter emphasizing the importance of safety and on commissioning the electrical system at a new facility was added. A chapter on reliability-centered maintenance was added on how to apply RCM and an extensive annex with detailed reliability data on many types of electrical equipment.


This edition did some reorganization to group like topics, and a chapter on testing and test methods for each individual equipment types were added to those chapters. A section on emergency preparedness and electrical system and equipment restoration was added to Chapter 6, including new material covering outsourcing of electrical equipment maintenance. The requirements on personnel safety were revised to correlate with and directly reference NFPA 70E.


Four new chapters were added: electrical disaster recovery, photovoltaic systems, electrical vehicle charging systems, and wind power electrical systems and associated equipment.


Torque recommendations were added to assist in minimizing electrical issues associated with poor connections. Battery testing and maintenance recommendations were enhanced to provide greater detail regarding proper battery testing and safety considerations for persons performing battery maintenance.

About the Author

Anna Townshend | managing editor

Anna Townshend has been a journalist and editor for almost 20 years. She joined Control Design and Plant Services as managing editor in June 2020. Previously, for more than 10 years, she was the editor of Marina Dock Age and International Dredging Review. In addition to writing and editing thousands of articles in her career, she has been an active speaker on industry panels and presentations, as well as host for the Tool Belt and Control Intelligence podcasts. Email her at [email protected].

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