What device allows the interconnection of two power sources without paralleling them?

The device that allows the interconnection of two power sources without paralleling them is the tie circuit breaker. Tie circuit breakers are specifically designed to connect two separate power sources in a manner that prevents their output from influencing each other directly. This is crucial because paralleling two different sources can lead to issues such as circulating currents, which can cause equipment malfunction or damage.

By using a tie circuit breaker, operators can switch between power sources or isolate one source without causing interference between them. This ensures both reliability and safety, as it enables maintenance or emergency procedures without compromising the overall electrical system's stability.

In contrast, options like fuses, circuit breakers, and switchgear serve different purposes, primarily focusing on protection, control, and management of electrical circuits. They typically do not facilitate the seamless interconnection of separate power sources in the same way that tie circuit breakers do.