In what scenario should a technician NOT work on an electrical circuit?

A technician should not work on an electrical circuit if they do not have the keys to the lock. In this scenario, the lack of keys means the technician cannot access the panel safely and securely, which is crucial for maintaining a safe work environment. Lockout/tagout procedures are fundamental in preventing electrical accidents, as they ensure that the power remains off while maintenance or repairs are conducted. If a technician cannot unlock the panel, they may be tempted to work around the lock, compromising safety protocols and increasing the risk of electric shock or injury. Having access to the keys allows for proper adherence to safety measures, ensuring that the electrical system is properly de-energized before any work begins.

In contrast, working on an electrical circuit is permissible when the power is shut off, when the panel is appropriately locked and tagged to signify that maintenance is taking place, and when the technician is adequately trained, as these conditions promote safety and minimize risks.