Under normal operation, what is the state of both incoming breakers and the tiebreaker?

In typical power distribution systems, especially for those managed by power engineers, the configuration of incoming breakers and a tiebreaker is crucial for ensuring a reliable and continuous supply of electricity. The correct scenario reflects the standard operating condition where both incoming breakers are closed, while the tiebreaker remains open.

When both incoming breakers are closed, it means that the system is actively receiving power from two different sources or feeds. This configuration provides redundancy and enhances reliability, allowing for maintenance work or operational adjustments to be made without interrupting power supply. Keeping the tiebreaker open during this state prevents the two incoming sources from being connected directly to each other, which could create a parallel operation situation that could lead to circuit instability or fault conditions.

The tiebreaker typically serves to connect the two incoming sources if one fails, allowing for a seamless transition and maintaining power continuity. In normal operation, it is designed to remain open to ensure safe and stable conditions, preventing potential back-feed or synchronization issues between the two systems.

In summary, having both incoming breakers closed and the tiebreaker open is essential for safe and effective operations in a power distribution setup, enabling reliable service while maintaining separation between the sources.