What is the first step in a lockout/tagout procedure when performing maintenance on a powered machine?

What is the first step in a lockout/tagout procedure when performing maintenance on a powered machine?

• A. Apply lockout devices
• B. Identify and isolate energy sources
• C. Verify zero energy before work
• D. Notify supervisor

Answer: (B)

Identifying and isolating energy sources must come first in any lockout/tagout procedure. Before you do anything to the machine, you need to locate all the ways energy can reach it—electrical power, hydraulic or pneumatic lines, mechanical energy, thermal sources, and any stored or residual energy. Once you know where the energy is coming from, you deliberately shut off or disconnect those sources and physically block them so the machine cannot be energized again during maintenance. This initial step is what prevents accidental startup from any source, including ones that might be overlooked if you jump straight to locking out. After the energy sources are identified and isolated, you apply lockout devices to maintain that state, then verify zero energy before beginning work. Notifying the supervisor or others may be part of the broader safety process, but it does not replace the essential first step of identifying and isolating energy sources.

Identifying and isolating energy sources must come first in any lockout/tagout procedure. Before you do anything to the machine, you need to locate all the ways energy can reach it—electrical power, hydraulic or pneumatic lines, mechanical energy, thermal sources, and any stored or residual energy. Once you know where the energy is coming from, you deliberately shut off or disconnect those sources and physically block them so the machine cannot be energized again during maintenance. This initial step is what prevents accidental startup from any source, including ones that might be overlooked if you jump straight to locking out. After the energy sources are identified and isolated, you apply lockout devices to maintain that state, then verify zero energy before beginning work. Notifying the supervisor or others may be part of the broader safety process, but it does not replace the essential first step of identifying and isolating energy sources.