What is meant by "isolated" in the context of electrical installations?

In the context of electrical installations, "isolated" refers to being not readily accessible to persons unless special means for access are used. This concept emphasizes the safety aspect of electrical systems, ensuring that certain components or systems are kept away from typical access to prevent unintentional contact or interference. Isolation in this sense implies that equipment or lines may be designed in such a way that they are protected from accidental engagement by unauthorized or untrained individuals, which is essential for maintaining a safe working environment.

To further understand this concept, it's useful to clarify the context of the other options. Being completely removed from all electrical connections does not align with the notion of isolation in this scenario, as isolation typically involves some electrical connection yet limits accessibility. Protection through a casing or enclosure is more about physical safety and environmental protection than isolation in terms of access control. Lastly, disconnection from power sources also does not embody the same meaning of isolation, as this might imply the component is inactive but not necessarily inaccessible.

Thus, the definition focusing on accessibility accurately represents what is intended by the term "isolated" in electrical contexts, ensuring that safety standards are upheld in installations.