What devices allow the main bus power to be disconnected to isolate switchboards?

Quick-open Bus Disconnect Links are specifically designed to allow for the rapid disconnection of bus power, effectively isolating switchboards. These devices operate by providing a mechanism that can quickly break the electrical connection in a bus system, which is crucial for maintenance, ensuring safety, and facilitating repairs without affecting the entire power distribution system.

In scenarios where isolation is required, these links help to prevent back-feed and ensure that maintenance workers can safely perform their tasks without the risk of electrical shock or equipment damage. Their design enables a swift action, which is essential in scenarios where time is critical for safety.

In contrast, the other options either do not focus on quick disconnection specifically for isolation purposes or serve different roles within the electrical distribution system. For instance, Bus Tie Connectors are meant to connect different sections of a bus system, thereby maintaining continuity rather than isolation. Switchboard Isolation Relays may control the isolation process but do not directly provide the physical disconnection like the Quick-open Bus Disconnect Links do. Quick-open Power Links could also imply connection capabilities rather than the specific need for isolation, thereby making them less relevant in this context.