What is the most critical action to take before working on electrical equipment?

The most critical action to take before working on electrical equipment is to ensure that it is de-energized and locked out. This step is fundamental in electrical safety practices, as it prevents any accidental energization of the equipment while work is being performed. De-energizing the equipment can include turning it off and ensuring that it cannot be turned back on unintentionally, typically through a process known as Lockout/Tagout (LOTO). This process involves placing locks and tags on energy-isolating devices to indicate that the equipment is not to be operated until the locks are removed by the person who placed them.

By ensuring that the equipment is de-energized and locked out, workers mitigate the risk of electrical shock, arc flash, or other serious accidents that can occur when working on live electrical systems. This practice is vital to maintaining a safe working environment and is a requirement outlined in various safety regulations and standards.

Other actions, such as notifying a supervisor or wearing protective gear, are important components of workplace safety and readiness, but they do not provide the direct protection that de-energizing and locking out the equipment does. Additionally, ensuring equipment is connected to power is contrary to safe work practices and increases the risk of injury.