The best way to answer this question is to review the two NFPA 70E articles 120 and 130. Article 120, Establishing an Electrically Safe Work Condition, provides the Lockout/Tagout requirements necessary to provide an electrically safe work condition for the employee. Article 130, Work Involving Electrical Hazards, has section 130.2 that requires that (1) exposed energized conductors (or parts) be put into an Electrical Safe Working Condition if you are within the Limited Approach boundary or (2) the employee is interacting with equipment where circuit conductors (or parts) are not exposed but an increased likelihood of injury from exposure to arc flash hazard exists.
Limited Approach boundary is the approach limit from an exposed energized equipment within which a shock hazard exists. For 480 volt equipment, this is 42 inches per Table 130.4(D). So the rules are to place equipment in an electrically safe work condition if the worker is within this 42 inches unless the energized equipment is justified per section 130.4(A).
Per Section 110.1 the employer in charge must complete a Job Safety Plan which includes the following:
- Description of the job and the individual tasks
- Identification of the electrical hazards associated with each task
- Conduct a shock assessment for tasks involving a shock hazard
- Conduct an arc flash assessment for tasks involving an arc flash hazard
So, when do I need an Energized Work Permit and how is this different? An energized work permit is required if the worker is performing work within the Restricted Approach Boundary. Per section 130.4(A) this is 12 inches for a 480 volt system or the worker is interacting with equipment where a circuit conductor (or parts) are not exposed but an increased likelihood of injury from exposure to arc flash hazard exists.
Similar to the job safety plan, the energized work permit has the same requirements as above and the additional requirement of “justification for why the work must be performed in an energized condition”. In both cases, one is required to conduct both a shock and arc flash hazard assessment.
Hopefully, this answers the question of when energized work begins or at least provides the requirements while working around electrical equipment.