If a utility defines their horizontal bus rotation as CBA, how should the customer proceed upon first connection?

The correct choice emphasizes the importance of maintaining proper phasing and phase sequence when connecting to a utility's system. In the scenario presented, the utility has specified their horizontal bus rotation as CBA. This indicates a specific phase sequence that must be respected to ensure compatibility with the utility's power system.

By leaving the phasing and phase sequence alone, the customer avoids any risk of phase misalignment. This is crucial because an incorrect phase sequence can lead to equipment malfunction, damage to three-phase motors or transformers, and other operational issues. It's essential for the customer to follow the established guidelines set by the utility to ensure a safe and effective connection without the need for adjustments or changes to the system.

Confirming the voltage rating is a good practice, but it does not directly address the importance of adhering to the defined bus rotation. Additionally, changing the bus rotation or disconnecting power might lead to unintended consequences that could complicate the connection process. Thus, maintaining the original phasing aligns with best practices and helps ensure a reliable electrical connection.