Implementing NFPA 70E in Your Electrical Safety Program
By Jay Smith, Executive Vice President of Lewellyn Technology
Implementing NFPA 70E is still a topic with which many organizations are struggling. The 2015 version of NFPA 70E introduced some changes on how you address electrical hazards in your facility. Although many organizations have completed the proper tasks to bring their facility into compliance with the standard, they still find the process of keeping their electrical safety program updated to be rather difficult. Electrical safety for your facility, and your employees, is not something you can simply check off of your “to-do” list. Your electrical safety program must be dynamic and constantly evolving to ensure the safety of your workers.
The 2015 version of 70E has placed more emphasis on calculating the incident energy for your electrical equipment. The requirements for labeling equipment based on the calculated incident energy have also changed causing quite a bit of confusion with regard to the PPE categories and selection methods. For those that have followed NFPA 70E closely for several years, we’ve become accustomed to hearing terms like HRC for Hazard Risk Category or “Cat 1, 2, 3, 4” referring to the PPE categories. The confusion centers around the elimination of these PPE categories when/if incident energy calculations have been performed on the equipment.
So what about all of your current PPE you ask? There is no need to panic. Updating your workers on the new NFPA 70E requirements and classifications for arc flash PPE can be handled with proper training. Your arc rated clothing systems should still be adequate, but you must ensure that the minimum incident energy rating (cal/cm^2) for the PPE is greater than the calculated incident energy rating for the equipment on which you will be working. Download our PPE poster from our website at https://lewellyn.com/ppe/?utm_medium=Website.Homepage.Resources&utm_term=2017.PPE.Poster.
How can you determine the incident energy rating?
In order to accurately determine the incident energy related to electrical equipment, you must complete an arc flash risk assessment. The four key components to an effective assessment include data collection, engineering analysis, mitigation, and equipment labeling. The data collection portion of the project, essentially an “autopsy” of the three-phase electrical distribution system, is one of the most important steps in the process as you must ensure that the equipment has been properly documented for the engineering portion of the project. During the data collection someone must physically visit the facility to collect information from your equipment like wire sizes and lengths, and breaker models and settings, among many other pieces of information. You cannot gather and verify this type of data in detail without actually being in front of the electrical equipment with the cover removed. One question we often receive is, “At what point in the system does the data collection end?”, and there are many different responses depending on to which arc flash service provider you speak. The main thing to remember is that an arc flash risk assessment is a safety study. The goal is to find hazards and, if possible, remove them from the system. Using that mindset, you must assess all of the equipment where your employees work–you cannot simply pick an arbitrary cut-off point in the system or estimate the hazard based on upstream devices.
*We recommend following the IEEE 1584 Standard to determine the guidelines for the arc flash assessment.*
Once data has been collected from the electrical distribution system, computer software is used to create a model of that system at which time single-line models are generated. Following the system modeling, the common practice at Lewellyn Technology is a series of four engineering assessments or analyses: A short-circuit analysis, interrupt rating analysis, protective device coordination analysis, and incident energy analysis.
Once these calculations are complete, the results must be documented and compiled into a report format so all potential hazards for the system can be summarized. As mentioned before, this is a safety study and it is vital that the arc flash report provides recommendations on how to mitigate possible hazards or remove them from the system. It is important to consider mitigating hazards on equipment where employees are exposed most, not just your main switchgear or larger pieces of equipment. A significant level of exposure is usually found on the floor level equipment since this is where your employees spend most of their time servicing and adjusting the equipment. PPE is the last line of defense and it is important to remove hazards whenever possible through engineering and modification to the current electrical system.
Equipment labeling and report delivery are the final steps in the arc flash assessment. We recommend that all of the equipment considered in the assessment receive a label to assure workers that the piece of equipment was analyzed during the initial assessment and the hazard rating is accurate. Although the 2015 NFPA 70E no longer recognizes Hazard Risk Category (HRC) 0 or Category 0, you can essentially consider this a terminology change because the non-hazard level for less than 1.2cal/cm^2 stills exists and requires no arc flash protection, only clothing made of non-melting fibers (and shock protection if over 50 volts). The new label for the old HRC 0 will now state that the equipment is less than 1.2cal/cm^2.
Implementing NFPA 70E can be a simple process, you just have to ensure you implement for the appropriate reasons and if you keep safety at the forefront of the process, the rest of the pieces will fall into place so that you can achieve both compliance and a safer workplace.