In November, I covered the layout of National Fire Protection Association (NFPA) 70, the National Electrical Code. Here, I discuss the layout and use of NFPA 70E and its relationship to NFPA 70.
NFPA 70E is designed to protect the electrical worker in the workplace. In many ways, the Occupational Safety and Health Administration (OSHA) offers a performance standard that instructs electrical personnel to protect their bodies from an electric arc blast. NFPA 70E was written at OSHA’s request and contains the means by which electrical personnel can select personal protective equipment (PPE) to wear when they are removing covers of enclosures for testing, troubleshooting or repairing energized electrical conductors and exposed circuit parts.
Chapter 1 is known as the 100 series and contains Articles 100, 110, 120 and 130. These articles deal with electrical equipment when covers are removed and workers are exposed to energized components. OSHA 1910.302 through 1910.308 covers situations where there are no openings in the enclosures that prevent totally enclosed conditions.
OSHA 1910.330 through 1910.335 deals with situations where the covers of electrical equipment are being removed, and energized electrical conductors and circuit parts are exposed.
Employees hurt or involved in a close-call accident have indicated that they failed to understand a term and, therefore, misapplied the safety requirement for a particular job task outlined in NFPA 70E.
Based on these interviews, committee members have carefully added definitions of terms throughout the standard that employees can apply to prevent misinterpretation.
For example, the term “exposed” has been revised and now contains the wording “energized electrical conductors or circuit parts.” This rewording was the committee’s effort to provide consistency when maintenance electricians apply this term in a particular job task.
If a term appears in two or more articles, it is eligible to be placed in Article 100 of NFPA 70E. However, other definitions are included in the articles in which they are used, but such terms may also be referenced in Article 100.
General requirements for electrical safety-related work practices
Article 110 covers requirements for employees who are exposed to electrical equipment that is not operating normally. If the requirements in Article 110 are applied appropriately, exposure to electrical hazards will be greatly reduced. It is the current in the circuit that determines electrical hazards and is directly related to the physical behavior of the equipment producing the energy. Such hazards usually are widely scattered throughout the production area in a facility.
The safety requirements cover both practices and procedures and are written to identify electrical hazards. Requirements also serve as an aid in protecting employees that are exposed to energized electrical conductors and circuit parts.
Establishing an electrically safe working condition
Article 120 clarifies that the most effective way to prevent an electrical injury is to deenergize the circuit and equipment and perform lockout/tagout (LOTO). Before LOTO is performed, determine all possible power sources or power supplies to the specific equipment.
Article 120 requires six basic steps to be applied for an electrical circuit or equipment to be placed in an electrically safe work condition.
Once accomplished as Article 120 permits, qualified and unqualified employees are allowed to work around the equipment.
Work involving electrical hazards
Article 130 deals with employees working on or near energized electrical conductors and circuit parts without establishing an electrically safe working condition on the power system. If an arc should occur, an employee who accepts such a risky task significantly increases the chances of injury, electrocution or equipment damage. Employees performing such work under the mentioned conditions must be trained and qualified to recognize and avoid contact with such hazards.
A written permit that justifies why this work must be performed under an energized condition must be provided. Several people usually review this work permit to verify if it is really necessary to perform the work while the electrical system is energized.
Remember, it can be considered if it is necessary to work while energized, if it’s not feasible due to the electrical system’s, components’ and equipment’s operating procedures. But never work energized for the sake of convenience.
There is not enough space here to include all the requirements in each article of NFPA 70E; therefore, please consider this article a basic description of 100, 110, 120 and 130.
STALLCUP is the CEO of Grayboy Inc., which develops and authors publications for the electrical industry and specializes in classroom training on the National Electrical Code and other standards, including those from OSHA. Contact him at 817.581.2206.