Hot or Not?
Why you need a better reason than mere inconvenience for working energized
NFPA Journal, March/April 2010
I get questions from a lot of people who share the notion that working on energized conductors and circuit parts is an acceptable practice, as long as the NFPA 70E® provisions for personal protective equipment are followed. NFPA 70E does allow you to perform energized work, but not at the carte blanche level of approval that some seem to think the standard allows.
Working energized has been a cultural phenomenon in many facets of the electrical industry. From a historical perspective, the Occupational Safety and Health Act (OSHA) of 1970 is a relatively new player, compared to the age of the electrical industry, especially when you consider how long electricity has been used in homes, businesses, and industry. We are living in an enlightened age when it comes to electrical safety, and the culture among practitioners is indeed changing. But there is still work to be done.
One cultural change we need is dispelling the notion that compliance with NFPA 70E is a means by which someone can work on energized equipment at his convenience or at the convenience of those directing the work. Nothing could be further from the OSHA requirements, which are federal law, or Section 130.1(A) of NFPA 70E. The requirements concerning energized work in the OSHA regulations and in NFPA 70E are in lockstep, and there are no deviations between the two.
The conditions for energized work are covered under three major headings, the first of which introduces the concept of “greater hazard.” That concept states that continuity of electrical power to some processes or equipment essential to prevent a catastrophic or life-safety hazard is of greater importance than the electrical hazard to which the worker performing a task will be exposed. The rationale for permitting energized work is similar to the substantiation used to support NFPA 70®, National Electrical Code®, rules covering the criticality of continuous electrical power, such as those in Article 695 for electric fire pumps.
The second limited provision under which energized work is permitted is a condition of “infeasibility,” which is an acknowledgement that there are testing and diagnostic tasks associated with the start-up or troubleshooting of equipment that can only be performed while the power is on. Continuous processes involving complex and extensive electrical systems are another example of a situation in which the condition of infeasibility can be considered in making the decision to perform energized work.
The third condition permitting energized work is where the circuit voltage is less than 50 volts to ground. For the purposes of this standard, the 50-volt benchmark is considered “low voltage,” but it is important to understand that under the right conditions, such as wet location contact, 50 volts can pose a potential shock hazard to personnel. Large installations of batteries operating at less than 50 volts can provide enough energy to produce an arcing fault.
As qualified safety instructors will tell you, the OSHA regulations and NFPA 70E have no provisions that recognize inconvenience as a viable rationale to support working on energized electrical conductors or circuit parts. Proper planning and logistical coordination are necessary to implement an electrical safety plan that only permits energized electrical work under the limited conditions covered in Section 130.1(A) of NFPA70E.
Before asking what the required level of personal protective equipment is for a specific task, you first have to ask whether the task can be performed when the electrical equipment is energized. Then—and only then—can you take the next steps in choosing the proper protective gear and procedure.
Jeffrey Sargent is NFPA's senior electrical specilist and is staff liason for NFPA 70E.