What is the notification time required before taking a facility outage for 500 kV and above?

The correct answer is 30 minutes because it reflects the established notification time required for conducting a facility outage at voltages of 500 kV and above in the context of transmission operations. This interval is crucial as it allows for sufficient communication among operators, coordination among different parties involved, and the implementation of necessary safety measures before the outage occurs. Timely notifications help ensure reliability in the transmission system by providing adequate time to manage load transfers and safeguard the network, thus preventing potential risks or disruptions resulting from the facility being out of service.