What is an isolation switch used for in a substation?

An isolation switch, commonly used in substations, serves the primary purpose of safely disconnecting circuits for maintenance or repair work. This is crucial to ensure that workers can perform tasks without the risk of electrocution or equipment damage. When a circuit is isolated, it is removed from the energized parts of the system, allowing maintenance personnel to work safely.

The switch functions by creating a physical break in the electrical circuit, ensuring that no current can flow through the system. This is particularly important during scheduled maintenance or unexpected repairs, where the safety of the personnel is paramount. By isolating a circuit, the rest of the system can continue operating normally, minimizing disruptions to the power supply.

In contrast, while some other options might intersect with various functions in a substation, they do not relate directly to the critical safety role that isolation switches provide during maintenance activities. For example, improving system efficiency typically involves operational strategies and not direct circuit disconnection. Increasing voltage is generally achieved through transformers and not isolation switches, and monitoring power usage relates to instrumentation rather than circuit isolation. Thus, the specific role of the isolation switch in disconnecting circuits for maintenance is foundational for safe and effective substation operations.