What must circuits energizing parts of fixed electric equipment be when an employee is exposed to potential contact?

When an employee is exposed to potential contact with circuits energizing parts of fixed electric equipment, it is essential that these circuits are properly locked out, tagged, or both. This practice is crucial for ensuring the safety of workers by preventing accidental energization of the equipment while maintenance or servicing activities are being carried out. Lockout/tagout procedures are designed to protect employees from hazardous energy during work on or near the equipment.

These measures not only communicate that a circuit is not to be energized but also visually and physically prevent its operation. By requiring a lock and tag, workers can be assured that no one will inadvertently restore power, thereby reducing the risk of electrical shock or other injuries. Safety regulations and best practices emphasize the importance of these procedures in maintaining a safe working environment.

The other options do not provide the same level of safety assurance. While hazard warning signs increase awareness, they do not physically prevent access or energization. Simply turning off the circuit at the main panel may not be sufficient, as it does not address the risk of someone inadvertently reactivating the circuit. Lastly, constant supervision, while useful, cannot guarantee safety as it does not prevent unauthorized access or accidental energization. Therefore, the most effective way to safeguard employees in this context is