After identifying all sources of electrical supply, what is the next required step?

After identifying all sources of electrical supply, what is the next required step?

• A. Stop running or operating equipment and then open all disconnecting devices for each source of electrical supply
• B. Visually verify the disconnecting device is fully open in the disconnected position
• C. Ground the phase conductors
• D. Test using a voltage meter

Answer: (A)

After identifying all sources of electrical supply, the next required step is to stop running or operating the equipment and open all disconnecting devices for each source of electrical supply. This creates a physical barrier that isolates the equipment from every potential energy source, ensuring no energy can flow to the equipment while work is being done. Isolating all sources is essential because one source being off doesn’t guarantee safety if others can still energize the circuit. Visual confirmation alone isn’t enough, since a disconnected device could be only partially opened or misidentified, and relying on grounding or voltage testing before proper isolation can still expose you to unexpected energization. Testing for absence of voltage is important, but it comes after the equipment has been de-energized and isolated.

After identifying all sources of electrical supply, the next required step is to stop running or operating the equipment and open all disconnecting devices for each source of electrical supply. This creates a physical barrier that isolates the equipment from every potential energy source, ensuring no energy can flow to the equipment while work is being done. Isolating all sources is essential because one source being off doesn’t guarantee safety if others can still energize the circuit. Visual confirmation alone isn’t enough, since a disconnected device could be only partially opened or misidentified, and relying on grounding or voltage testing before proper isolation can still expose you to unexpected energization. Testing for absence of voltage is important, but it comes after the equipment has been de-energized and isolated.