What measures must be taken during ground operations concerning electrical power?

During ground operations, the limitation regarding DC only operations being limited to five minutes ensures that critical systems receive adequate electrical power while avoiding potential battery depletion. In an aircraft like the CRJ 200, the batteries are designed to support electrical power for a limited duration when the engines are not running and the generators are not providing power.

This limitation is key for maintaining operational safety. If the DC power is drawn beyond this five-minute threshold, there is a risk of draining the battery to a point where it may not be able to start the engines or support essential avionics during takeoff or emergency situations. Thus, pilots and ground crew must monitor electrical power usage closely, ensuring that operations relying solely on battery power are limited to this timeframe to safeguard the aircraft's readiness and systems integrity.

In contrast, measures such as requiring an alternate power source, total systems shutdown, or limiting power to battery only do not directly align with the critical balance of maintaining power availability while preventing battery overuse in an operational setting. These alternatives could lead to unnecessary operational complications or reduced functionality during ground operations.