How is the DC system reconfigured in the event of a TR failure?

In the event of a TR (Transformer Rectifier) failure in an A320 aircraft, the DC system is designed to maintain functionality by reconfiguring the buses. The correct answer highlights that DC buses 1 and 2 will interconnect through the DC BATT bus, which allows for the continued distribution of electrical power even when one of the transformer rectifiers fails.

This interconnection ensures that critical systems have access to backup power, maintaining operational integrity and safety. The DC BATT bus can step in to provide power to both buses, allowing for redundancy and minimizing the risk of a total power loss to the systems reliant on those buses. This capability is vital for maintaining aircraft operations during abnormal conditions.

Other options may describe scenarios that don't align with how the A320's electrical system is designed to respond to such failures. For example, simply losing the associated DC bus and DC BATT bus would not support continued power distribution, while the static inverter being automatically powered would not be relevant in the context of addressing a TR failure specifically. Lastly, although the ESS TR (Essential Transformer Rectifier) does have a supportive role, the specific mechanism that allows for continued functionality in a TR failure involves the interconnection through the DC BATT bus.