NFPA 70E and Condition of Maintenance: Do You Know About Informative Annex S?

Ron Widup, Shermco IndustriesColumns, NFPA 70E and NETA, Summer 2024 Columns

Condition of maintenance: It’s a term found in NFPA codes and standards, but do you really understand what it means? If not, check out Informative Annex S Assessing the Condition of Maintenance, in the 2024 edition of the NFPA 70E.


Where is condition of maintenance referenced in 70E? Let’s look at a few relevant sections: 

  • The general requirements in Section 110.3 state that the condition of maintenance, which can be found in Section 110.3C, must be addressed:

    110.3(C) Condition of Maintenance
    The electrical safety program shall include elements that consider condition of maintenance of electrical equipment and systems.
  • Annex S Section S.3 Electrical Safety Program clearly states that you must consider condition of maintenance in your electrical safety program:

    the employer shall implement and document an overall electrical safety program that directs activity appropriate to the risk associated with electrical hazards. 
  • This is further clarified in Section 110.5 Host and Contract Employers’ Responsibilities, which also states:

    110.5(C) Condition of Maintenance
    An electrical safety program must consider the condition of maintenance of the equipment and its component parts.

    Now you have a clear requirement under general terms, and you have a specific requirement if you are a host employer — or a contract employer — to consider condition of maintenance in your electrical safety program.
  • Article 205 tells us:
    ….safe normal operation of equipment is dependent on the condition of maintenance.


Let’s start with the definition of “Condition of Maintenance,” which is the same in NFPA 70B, Standard for Electrical Equipment Maintenance, and NFPA 70E, Standard for Electrical Safety in the Workplace:

Condition of Maintenance. The state of the electrical equipment considering the manufacturers’ instructions, manufacturers’ recommendations, and the applicable industry codes, standards, and recommended practices.

Now let’s dissect the definition and the meaning just a bit.

Part 1

The state of the electrical equipment…

It seems obvious, but don’t pass it by. It’s the overall condition of the equipment as you walk up to and begin to interact with it (Figure 1). Is it new? Service aged? Clean? Dirty? Good condition? Poor condition? All those factors need to be considered.

Figure 1: Medium-Voltage Circuit Breaker Testing
How well equipment has been cared for is part of the condition of maintenance analysis.
Part 2

…Considering the manufacturers’ instructions, manufacturers’ recommendations…

That overall condition you just thought about — now you need to apply further reasoning and analysis, taking into account:

  • How well has it been cared for?
  • What environment does it live in?
  • Is the environment suitable?
  • Is the equipment rated for your application?
  • How did the original manufacturer expect you to use it?
  • Has it been installed in an area as intended and designed?

These considerations can affect things greatly if not answered correctly!

Part 3

…[Considering] applicable industry codes, standards, and recommended practices.

Finally, have the previous two components been considered in conjunction with best practices and industry consensus? Are you looking after it properly and maintaining it in accordance with what those in the industry say you should? This is another important aspect of the definition and an important piece of the overall definition.


Remember, operating condition and condition of maintenance are two different things! Maintenance is just one part of normal operation. Other elements of operating condition include:

  1. The equipment is properly installed.
  2. The equipment is properly maintained.
  3. The equipment is rated for the available fault current.
  4. The equipment is used in accordance with the instructions included in the listing and labeling and with the manufacturer’s instructions.
  5. The equipment doors are closed and secured.
  6. All equipment covers are in place and secured.
  7. There is no evidence of impending failure (Figure 2).
Figure 2: Medium-Voltage Cable Condition
Environment and evidence of impending failure must be considered before interacting with equipment.


OK…condition of maintenance, I get it — you have to understand what shape the equipment is in, and it’s clear that Article 205 states safe operation is dependent on it… but where can you look for guidance in the 70E for condition of maintenance? The answer: Look to Informative Annex S.

Informative Annex S provides guidance for understanding the condition of maintenance. Here’s an abbreviated summary of the information. For a complete review, study NFPA 70E.

S.1 Introduction

The objective of these requirements is to emphasize the inherent risk to workers associated with performing tasks on electrical equipment that is not properly rated, not properly installed, has not been properly maintained, or otherwise exhibits evidence of an increased risk level for electrical workers or operators. 

S.2 Assess the Risk

Safe work practices should always be used when gathering information to be used to assess the condition of maintenance of electrical equipment. 

S.3 Visual Inspection

Visual inspection of equipment (Figure 3) can be used to verify that it is installed professionally and skillfully in accordance with applicable industry codes and standards and the manufacturer’s instructions. 

Figure 3: Transformer Gauges
Visual inspection is an important aspect of overall risk assessment.
S.4 Periodic Testing and Inspection

Periodic testing and detailed inspection methods are used to help workers determine the condition of the equipment at the time of the test. 

S.5 Permanently Installed Monitoring

Continuous monitoring of specific equipment conditions can be performed using an uninterrupted method of data collection. The use of real-time data is useful when determining the condition of the equipment and is also used to modify (shorten or lengthen) the predetermined maintenance intervals for other inspections and tests.

S.6 Predictive Techniques

These technologies and methods often detect minor items before they propagate into major issues or equipment failure, enabling workers to interact with or operate the equipment while it is still in a normal operating condition as opposed to an abnormal condition.

S.7 Maintenance History

The maintenance history of electrical equipment is an important factor to consider when assessing if the equipment has been properly maintained in accordance with the manufacturer’s recommendations and applicable industry codes and standards. 

Figure 4: Condition of Maintenance Labels
  • S.7.1 Labels
    Labels, decals, or other markings might be color-coded and placed on the exterior enclosure or surface of the electrical equipment or device to communicate the condition of maintenance as of the last assessment. 
  • S.7.2 Digital and Other Electronic Methods
    Digital technology is used as a method of storing and sharing maintenance-related information. 
S.8 Standard for Electrical Equipment Maintenance

NFPA 70B provides a means to establish and maintain an acceptable condition of maintenance of electrical equipment and systems to address safety and reliability.


And finally, of course, if you apply the guidance provided in the ANSI/NETA testing standards to your electrical equipment, you can be assured that the proper visual, mechanical, and electrical tests have been performed on the equipment, which ultimately leads to a safer and more reliable power system.

Read the standards; understand the content. You’ll be glad you did! 

Ron Widup is the Vice Chairman, Board of Directors, and Senior Advisor, Technical Services for Shermco Industries and has been with Shermco since 1983. He is a member of the NETA Board of Directors and Standards Review Council; a Principal member of the Technical Committee on Standard for Electrical Safety in the Workplace (NFPA 70E); Principal member of the National Electrical Code (NFPA 70) Code Panel 11; Principal member and Chairman of the Technical Committee on Standard for Competency of Third-Party Evaluation Bodies (NFPA 790); Principal member and Chairman of the Technical Committee on Recommended Practice and Procedures for Unlabeled Electrical Equipment Evaluation (NFPA 791); a Principal member of the Technical Committee Standard for Electrical Equipment Maintenance (NFPA 70B); and Vice Chair for IEEE Std. 3007.3, Recommended Practice for Electrical Safety in Industrial and Commercial Power Systems. He is a member of the Texas State Technical College System (TSTC) Board of Regents, a NETA Certified Level 4 Senior Test Technician, State of Texas Journeyman Electrician, a member of the IEEE Standards Association, an Inspector Member of the International Association of Electrical Inspectors, and an NFPA Certified Electrical Safety Compliance Professional (CESCP).