What does NFPA 70E® say about an electrically safe work condition?
The 2021 edition of NFPA 70E® Standard for Electrical Safety in the Workplace requires equipment to be placed in electrically safe work condition (ESWC) anytime a worker is exposed to an arc flash or electrical shock hazard.
What if an electrically safe work condition cannot be established?
However, there are times when an electrically safe work condition cannot be established, or the risk is such that an ESWC is not necessary. If the job plan or risk assessment permits energized work, then adequate risk controls must be implemented, and per NFPA 70E® 110.4(A)-(D), one of these four conditions must exist:
The task cannot be performed with the equipment in an electrically safe work condition or an ESWC is infeasible due to equipment design. Examples of this would be testing, measuring, or troubleshooting, or if the task is being performed on equipment that cannot be deenergized, like solar photovoltaic systems or storage batteries.
When creating an electrically safe work condition may cause a greater hazard. Examples include life support equipment in an intensive care unit, continuous ventilation system for volatile gasses in a hazardous location, or cooling water systems for a furnace refractory material.
If the worker is exclusively exposed to voltages less than or equal to 50V. Arc flash and shock hazards are unlikely to be present at these voltage levels. Provided the energy source and overcurrent protection do not pose any additional risk of injury from electrical burns or explosions due to arcing, the risk to employees is sufficiently low.
During “normal operation” of electrical equipment. Normal operation is the operation of a switch, circuit breaker, disconnect, or similar if the equipment is a) installed per manufacturer’s instructions and enforceable codes; b) all doors and covers closed and securely fastened; c) there is no evidence of impending failure as observed through excessive temperatures, unhealthy sounds, visual anomalies, or unusual smells; and d) the equipment is properly maintained as per manufacturer’s instructions and consensus maintenance standards and guidelines.
If any of these requirements is not met, then the equipment is in an “abnormal state,” and other means of operation should be adopted. This may include creating an electrically safe work condition on the upstream equipment or performing remote operation (if catastrophic failure of the equipment will not endanger workers or result in cascading damage to other equipment).
In "normal operation," are shock and arc flash protections needed?
We are often asked the question of whether “normal operation” requires any PPE.
PPE used for protection against electrical hazards may include a combination of electrically insulated (for arc flash protection) and mechanically rated (for debris and projectiles).