For a delta-connected system, what is the minimum ampacity requirement for the grounded conductor?

In a delta-connected system, the grounded conductor plays a critical role in maintaining the safety and functionality of the electrical system. The requirement for the grounded conductor to match the ampacity of the ungrounded conductors ensures that it is adequately sized to handle potential fault currents and maintain system integrity. This sizing is essential because, during fault conditions, the grounded conductor may carry a significant return current. If it is not appropriately sized, it could overheat, lead to failures, or present safety hazards.

Furthermore, matching the ampacity does not only promote safe operation but also ensures efficient system performance by allowing all conductors to operate under identical thermal conditions. This helps in preventing imbalances and potential issues in the electrical distribution system.

With this requirement in mind, other options do not align with the established safety practices and guidelines in electrical installations.