And so, the world turns. As new research is conducted, old topics debated and best practices refined, the world's most influential electrical safety standards evolve to keep pace. And now, sometime before the golf season ends and deer season begins, NFPA 70E and CSA Z462 are set to release their latest revisions.
The following is a brief summary of some of the more significant changes and evolutions with some insight regarding the reasons for the revisions. This overview is not intended to be all-inclusive, nor is it intended to be a replacement for reading the standards in their entirety. At best, it is an attempt to provide readers with an indication that they will need to:
Purchase a copy of the new revision,
Study the modifications to the text,
Consider how the changes might influence their documented electrical safety programs.
It is also important to note that the changes anticipated herein are based on the most recent drafts and final committee balloting, however, the final revision could differ based on the results of final edits, approvals and votes that could affect the final text. (Note: Because CSA Z462 is harmonized with NFPA 70E and the differences are minimal, this article will focus primarily on NFPA 70E.)
Concepts of Hazard and Risk
The 2012 revision of NFPA 70E and CSA Z462 made several changes to separate the concepts of hazard and risk. The two concepts deserve to be separate and are, in fact, distinct concepts in other occupational heath and safety (OHS) standards. The 2015 revisions of NFPA 70E and CSA Z462 continue this effort to separate and clarify these important, foundational concepts.
Hazard, hazardous, risk and risk assessment have all been added to the Definitions section, further delineating and separating the use of those terms.
Whereas a hazard is the source of potential injury or damage to a worker's health, risk is a combination of the likelihood and potential severity of that injury.
Consequently, any references to the hybridized hazard/risk categories (HRC) have been replaced with the more accurate and descriptive personal protective equipment (PPE) category.
The various forms of hazard analyses have been changed to risk assessments, which:
Identify the hazard(s),
Estimate the potential severity and likelihood of injury/harm,
Determine what, if any, protective measures are appropriate.
These changes might not appear significant at first glance, but they are significant in the way they bring these standards in line with other safety standards. And as you will see, they have a great deal of impact on the task tables in NFPA 130.7(C)(15).
Other Global Changes
The term harm has been clarified to read, "injury or damage to health'." Because probability has the connotation of a mathematically derived calculation, the 2015 revisions of 70E and Z462 will refer to the likelihood" of an event.
In a continuation of the effort from the 2012 revision, all references to flame resistant (FR) are changed to arc resistant (AR). It is an important detail that seeks to eliminate any potential confusion with regard to PPE that is appropriate for use around a potential arc flash hazard.
Traditionally, the scope of NFPA 70E has seen very few changes over the years. This cycle, however, brings about a few notable exceptions. For consistency with related standards and industry best practices, and to emphasize the importance of safety-related maintenance and administrative controls (e.g., training), the revised scope will also include safety-related maintenance requirements and other administrative controls. The committee also added an informational note warning that the highest risk of electrical-related injury "for other workers involve unintentional contact with overhead power lines and electric shock from machines, tools and appliances..." The addition of this note to the scope continues the efforts to emphasize that electrical safety is something that affects workers across the organization, not just the electrical group.
The most significant change to the scope, however, resulted from a Mine Safety & Health Administration (MSHA) decision to accept the NFPA 70E standard in much the same way that OSHA does, making it a de facto electrical safety standard for the mining industry. Consequently, the exemption for mining applications previously found in the scope [Section 90.2(B)] will be removed in 70E-2015.
Prohibited Approach Boundary
The prohibited approach boundary (i.e., the distance from a conductor that was considered the same as making contact) has been eliminated from the definitions after some interesting debate.
Those who advocated for its continued inclusion in the standard generally thought that it underscored the difference between working in contact with the conductor versus working in proximity that would require shock protection.
The committee determined that previous changes to the standard have made the prohibited approach boundary obsolete since it no longer triggers any behavior on the part of the worker or manager. Generally speaking:
The limited approach boundary defines the boundary for unqualified workers.
The restricted approach boundary defines the area in which qualified personnel are required to utilize PPE to prevent shock.
The arc flash boundary defines the area where arc resistant PPE is required.
But the prohibited approach boundary had no actual instructional value within the standard and no requirements associated with it. It had essentially become an answer to a trivia question. The committee ultimately decided that the term added a layer of complexity and was a possible source of confusion without actually adding any direction to the user.
Maintenance and Your ESP
The electrical safety program (formerly 110.3) is being moved to the beginning of Article 110, General Requirements for Electrical Safety-Related Work Practices, to provide clarity since the implementation of an electrical safety program (ESP) would naturally be the first element of the section an employer would address, followed logically by the other section considerations, such as training, relationships with contractors, etc.
As with the 2012 revision and as seen earlier within the scope, maintenance is once again being placed front and center as a keystone of electrical safety. After the mandate that the employer must implement an ESP, the first consideration listed [110.1(B) Maintenance] is that the ESP must give consideration to the equipment maintenance.
Because improperly or poorly maintained electrical equipment can result in failures and longer clearing times, personnel safety is directly affected by the condition of the equipment in their proximity. It only makes sense that the standards would continue to focus attention on the condition and maintenance of the equipment. This will be evident again in the task tables in Article 130.
Auditing and Training Intervals
Auditing the ESP [110.1(I)] will continue to be required at intervals of three years or fewer. But the audit of field work to verify that workers and managers are following the ESP procedures now will be required at least annually. Previously, there was no prescribed interval.
Annual auditing of field work actually brings the section in line with various training intervals required in Article 110.2 (Training Requirements) of the standard. The annual training or refresher is required for aspects of emergency response training, including contact release, CPR and AED, as well as for training verification.
Do you wear a full bomb suit when plugging in your laptop or walking past a motor control center (MCC)? Then you will be very interested to learn about the normal operations clause to the Energized Work [130.2(A)] section.
Past revisions added informational notes to indicate that enclosed electrical equipment that has been properly installed and maintained and is under normal operating conditions is "not likely" to pose a hazard. NFPA 70E-2015 will move this concept to the body of the standard, giving the reader clear direction that normal operation of equipment will be permitted as long as the equipment is properly installed and maintained, doors and covers are closed and secured, and there is no evidence of pending failure. These points are echoed in the task tables in Article 130.
Energized Electrical Work Permits
The requirements around energized electrical work permits (EEWPs) have been loosened and clarified. No longer are the limited approach boundary or the arc flash boundary triggers for requiring an EEWP. Instead, the permits will be required when working inside the restricted approach boundary and, as previously, when conductors are not exposed, but there is an increased risk of injury due to arc flash.
The exemptions to work permit also saw clarifications. As before, a permit is not required for testing and troubleshooting. Thermography, visual inspection, general housekeeping, access and ingress with no electrical work are all exempt when done outside the restricted approach boundary. An exemption also exists for tasks that a risk assessment determines has no arc flash hazard.
Selection of Arc Flash PPE
The committee has added additional language to stop the all too common practice of mixing the method of selecting appropriate PPE. Users may use either the incident energy analysis method or the arc flash PPE selection categories method (formerly referred to as the hazard/risk categories method), but not both on the same piece of equipment.
Furthermore, sites that perform an incident energy analysis to generate the arc flash hazard analysis labels are not permitted to compare the calculated cal/cm2 value to the arc flash PPE levels from the tables and then list the arc flash PPE level on the labels. Instead, PPE selection based on specific cal/cm2 requirements would be appropriate.
Similar restrictions are repeated in the labeling requirements, stating that the incident energy or PPE category can be listed on the labels, "but not both."
No "Bling" Zone
Jewelry wearers take note: The standard has clarified an ambiguity with regard to when conductive articles, such as watches, necklaces, etc., can be worn. Quite simply, leave the bling in your locker when you are going to be working within the restricted approach boundary.
Arc Flash Hazard Identification Table
Gone are the traditional hazard/risk category classification (HRC) tables. The former table method for selecting PPE was based on classifications of equipment, which, in turn, is based on the voltage, available fault current, clearing time and minimum working distance, and the risk associated with the task. Consequently, lower risk tasks required less PPE than higher risk tasks despite the fact that the thermal energy produced in an arc flash incident is in no way affected by the risk of the task. The potential result was a worker being under protected.
It is worth pointing out that there has been no evidence to indicate that workers have been injured as a result of being under protected when using the table method. However, the potential was there and the committee addressed the potential issue proactively.
The new table method for PPE selection separates the tasks and arc flash PPE selection into two discrete tables. The new task table identifies whether the task requires arc flash PPE. The determination is based on whether the task increases the risk of triggering an arc event and whether the equipment condition should be trusted using the same criteria as that under normal operation (i.e., properly installed, properly maintained, covers secured, no evidence of impending failure). The task table combines the previously separate AC and DC tables into one table.
After the task table indicates that the task or equipment condition requires personnel to utilize arc flash PPE, the user is instructed to consult the arc flash PPE categories table to determine what level of PPE is required. PPE requirements are based on the equipment parameters similar to previous revisions (i.e., voltage, available fault current, clearing time and working distance). Whereas, previous revisions listed various levels of PPE for a category of equipment, now there is simply one level of PPE prescribed for each category of equipment.
Arc flash boundaries is a new column in the arc flash PPE categories table. The arc flash boundary has been rounded up to the nearest foot for equipment falling into Category 2 or higher. Gone is the column indicating the requirement for rubber gloves. Similarly, the column for insulated tools no longer exists, but the Insulated Tools and Equipment section was modified so the trigger to utilize insulated tools is now the restricted approach boundary as opposed to the limited approach boundary as with the 2012 revision.
PPE Category 0
Category 0 PPE, formerly HRC 0, is no longer listed in the PPE tables.
Because users only consult the arc flash PPE categories table when they require arc flash PPE, any PPE listed in the table would have to be arc resistant. The former Category 0 was not actually arc resistant since the cotton could ignite, it simply didn't melt. Eliminating Category 0 ensures that personnel who are at risk of encountering an arc flash will be dressed in materials that are arc resistant, which Category 0 never was.
One common complaint that people have with the elimination of Category 0 is that personnel will see it as a green light to begin wearing meltable fabrics when working with electrical applications. However, it should be pointed out that a facility's ESP can require personnel to wear more conservative attire by making it part of its ESP and site-specific policies. Furthermore, there are numerous references to the prohibition of wearing meltable fabrics as or with PPE.
The task of performing infrared thermography outside the restricted approach boundary does not require the use of arc flash PPE, as long as the equipment is properly installed and maintained, with secured covers and no impending failure. This will make performing infrared (IR) scans far more comfortable and easier for those who do not yet have IR windows to make the task safer and more efficient.
However, there are two important points to be made:
If for any reason the equipment condition is suspect (e.g., not properly installed, not properly maintained, covers not secured, or evidence of impending failure), the thermographer would need to wear appropriate arc flash PPE.
The workers who are opening the hinged doors or removing bolted panels to expose the conductors for the thermographer's inspection are engaged in an inherently high-risk task, one that could trigger an arc flash event. Therefore, the workers who are opening the equipment still need to wear PPE appropriate to their potential exposure.
A clarification was also made with regards to barricades. They are to be placed at the distance defined by the limited approach boundary or the arc flash boundary, whichever is greater.
Safety-Related Maintenance Requirements
NFPA 70E-2015 and CSA Z462-2015 consistently bolster references to maintenance and continue to drive home the importance of properly maintaining electrical equipment as an integral aspect of electrical safety. As indicated earlier, the electrical safety program must now give consideration to equipment maintenance and, for the first time, users of the tables are required to consider equipment condition as part of their arc flash risk assessment. Maintenance is truly taking center stage in the 2015 revision.
Article 200: Safety-Related Maintenance Requirements continues that emphasis. A new informational note refers readers to the Institute of Electrical and Electronics Engineers' IEEE 3007.2-2010 Recommended Practice for the Maintenance of Industrial and Commercial Power Systems. Then, under general maintenance requirements, it makes the point that the equipment owner or its representative is responsible for maintenance of the electrical equipment.
A new informational note was also added to suggest a system of labels to indicate calibration, condition and inspection status, again providing the worker with critical information about condition and maintenance.
Finally, an informational note was added to point out that improper maintenance of protective devices can result in increased clearing times, which results in higher incident energy.
This latest revision to NFPA 70E contains several changes that are significant enhancements for safeguarding workers who may encounter electrical hazards on the job. The committee's members should be applauded.
There is no substitute for studying the standard in its entirety. This summary is not an all-inclusive detailing of the standard. Anyone who works with electricity or who manages those who do are strongly encouraged to purchase and study this important, life-saving standard.
Tim Rohrer is Founder and President of Exiscan LLC, a manufacturer of industrial electrical safety products including infrared windows, visual inspection windows and ultrasound ports. Tim has over a decade experience in the predictive maintenance industry and is a Level 2 Thermographer. He is a member of IEEE Industrial Applications Society, a committee Chair for the IEEE IAS Electrical Safety Committee and a committee Chair for the IEEE IAS Electrical Safety Workshop. www.exiscan.com
Keep reading...Show less
“R.A.I.” the Reliability.aiTMChatbot
You can ask "R.A.I." anything about maintenance, reliability, and asset management.