The Trilogy of Electrical Safety

There are a number of changes that have been introduced in 2014 that will affect people working on or near exposed live (energized) circuits.  Over the next couple of months, I will explain a few of the most important changes detailed in NFPA 70E.  In general, the 2015 edition of The Standard for Electrical Safety in the Workplace (NFPA 70E) reflects changes that make sense.

Before looking at the details, one must consider a holistic approach to safety to obtain a complete picture.  There are three standards that affect the interaction of people with electrical hazards.  These are the National Electric Code (NFPA 70), The Standard for Electrical Safety in the Workplace (NFPA 70E), and Recommended Practice for Electrical Equipment Maintenance (NFPA 70B).  To workplace free from electrical hazards, one needs to make sure that all three standards are used.

The National Electric Code (NEC) provides the basic requirements to ensure that equipment is installed properly.  The NEC describes the “normal” operation of equipment.  When equipment is designed and installed in accordance with the NEC, at that point there is minimal potential electrical hazards: shock hazards or arcing hazards.  For example, an electrical panel installed in accordance with the articles in NFPA 70 Chapter 408 does not present a shock or arc flash hazard when the deadfront covers are properly installed. 

The Recommended Practice for Electrical Equipment Maintenance standard provides the basic requirements for properly maintaining equipment.  This includes the development of an electrical preventative maintenance (EPM) program and recommended practices for equipment and conductors.  NFPA 70B provides the requirements after the equipment has been installed and operated, and subsequently temporarily removed (de-energized) from service for maintenance.  For example, an electrical panel has been de-energized, locked out and tagged out, and is undergoing examination and testing of the panelboard itself, the internal molded case circuit breakers (MCCBs), and the conductors entering and exiting the panelboard.

The Standard for Electrical Safety in the Workplace provides the basic requirements for working on equipment in an “abnormal” condition.  It is an abnormal condition as the equipment is not being used as intended nor is it being maintained.  For example, an electrical panelboard undergoing voltage testing to determine if circuits are operating properly is an abnormal condition.  In this scenario, the deadfront covers are removed and personnel are exposed to live (energized) parts.  Because there is an interaction with exposed live (energized) circuits, there is a shock hazard risk and an arc flash hazard risk.

Many consider that the safety of personnel from shock and arc flash hazards are only associated with the practices detailed in The Standard for Electrical Safety in the Workplace.  However, this is not true.  Safety from electrical hazards starts with the proper installation of equipment, followed by the proper servicing and maintenance of the equipment.  When the equipment is properly installed and maintained, then qualified personnel following safe work practices and using proper personal protective equipment (PPE) can work on exposed live (energized) circuits under specific conditions.