What does the grounded primary neutral of an open wye-open delta transformer bank carry?

In an open wye-open delta transformer bank, the grounded primary neutral plays a crucial role in the circuit's operation. It is responsible for maintaining a balanced phase-to-neutral voltage and ensuring system stability.

The grounded primary neutral carries full primary current under certain conditions, particularly when there is a balanced load on the transformer. This means that even in an open delta configuration, the neutral must be able to handle the entire current flow from the primary windings to ensure the delivery of power effectively.

It's essential to understand that the design of transformer systems means the neutral point is necessary to maintain the integrity of phase voltages and to ensure that the system can support full current without risk of overloads or imbalances. This characteristic is particularly important in three-phase systems where balancing loads is critical for performance. Therefore, this grounding also assists in safety by providing a return path for fault currents, which can occur in a balanced system.

Thus, the correct answer indicating that the grounded primary neutral carries full primary current is aligned with the operational principles of transformer bank systems, especially in the context of maintaining system balance and safety.