A data center that depends on multiple energy sources must manage more than electricity generation and distribution. Generators, battery energy storage systems, inverters, utility connections, protection relays, and facility controls each perform specific functions, but their combined behavior determines whether the site can maintain a stable electrical supply. This creates a commissioning challenge that equipment-level acceptance procedures cannot resolve on their own. A generator can meet its rated output, a battery can respond to dispatch commands, and an inverter can regulate voltage within its specified operating range without proving that these assets will respond correctly during a sudden utility disturbance. The challenge becomes particularly important when the facility must transfer between grid-connected and islanded operation without exposing critical loads to unacceptable voltage or frequency excursions. Commissioning must establish whether the entire electrical architecture can execute those operating sequences under realistic conditions.