When properly executed, the process of lockout and tagout allows workers to quickly and safely perform tasks on electrical circuits that have been de-energized. However, an electrical circuit that has been locked and tagged at a panel source might still have some exposed electrical conductors that can be harmful to employees.

For example, the main terminals could still be energized while circuits that feed the panel are off. Optimal safety performance has not been achieved, and placing workers in this scenario could result in an Error Provocative Environment. Environmental awareness needs to be maintained so the employee doesn’t have a false sense of protection. An option that would make this task safer would be to turn off the circuit that feeds the panel further downstream. Another practical solution would be to use insulating blankets that are rated and have been tested for the voltage. 

Don’t become complacent. Before working on any electrical circuit, workers must test for the absence of voltage. The electrical tester first needs to be tested at a known source to ensure it is working properly. Remember, a voltage tester must be rated for the application for which it is being used. Additionally, make sure the selection process for lockout and tagout devices is clear, as not all devices are adequate for every task.

For more information, reference the latest version of the Standard for Electrical Safety in the Workplace: NFPA 70E.


Jerry E. Rivera is regional safety director for Power Design and a member of the ABC National Environment, Health and Safety Committee. For more information, email jrivera@powerdesigninc.us or visit abc.org/safety.