What characterizes a closed transition?

A closed transition is characterized by the new power source being connected to the load before the original power source is disconnected. This method ensures that the transition between power sources occurs without interrupting the supply to the system, which is critical in applications where maintaining continuous power is essential, such as in data centers or critical infrastructure. The fact that the new power source breaker is closed before the original breaker is opened allows for a seamless transition with no momentary power loss.

In such a transition, there may be a brief period when both sources are connected to the load, which is what differentiates it from an open transition, where the load would experience a complete power loss during the switching process. Maintaining power throughout the transition is crucial for the reliability of the system, as it avoids disruptions in service.