Safety, NFPA 70E, and Job-Site Practices
NFPA 70E is about how the work is done, not how it is built. The exam tests the hierarchy of controls, approach boundaries, risk assessment, PPE selection, lockout/tagout, and meter safety.
Core requirements
- 130.2: energized work is permitted only when de-energizing would introduce an increased hazard or is infeasible due to equipment design or operational limitations. Otherwise the circuit must be de-energized.
- 130.4 shock protection: for 480 V exposed fixed parts, the limited approach boundary is 3 ft 6 in and the restricted approach boundary is 1 ft.
- 130.5: an arc flash risk assessment establishes the arc flash boundary, incident energy, and PPE. When an incident energy analysis exists, it governs over the PPE tables.
- 120.1 through 120.5: lockout/tagout, verification of the absence of voltage with a tester proven on a known source, and application of locks.
- Test instruments must carry a CAT rating appropriate to the point of measurement: CAT IV at the service, CAT III at feeders and panelboards, CAT II at branch circuits and cord-connected loads.
Worked example
A journeyman is to torque the lugs of a 480 V MCC bucket on a continuous process line. The line can be shut down Saturday, so de-energizing is feasible and the energized work permit is not available. If the shutdown were truly impossible, the sequence would be: energized work permit under 130.2(C), risk assessment, PPE with an arc rating at or above the incident energy, shock protection to the restricted approach boundary, and a CAT III 600 V meter. A CAT II 1000 V meter has enough voltage rating but not the transient rating for that location, so it is the wrong instrument.
Traps
- Reading "can't shut down" as infeasible when a scheduled outage exists.
- Using the PPE tables when an incident energy analysis is available.
- Wearing voltage-rated gloves past their test date.
- Treating a low-voltage circuit as automatically safe.