What is the main subject of Article 700 in the NEC?

The main subject of Article 700 in the National Electrical Code (NEC) pertains to Emergency Systems. This section is specifically focused on the requirements for systems that provide power to essential electrical loads during outages or emergencies. Emergency systems are crucial for ensuring that life safety systems and other critical loads remain operational when the normal power supply fails.

The provisions outlined in Article 700 address the design, installation, and maintenance of emergency power systems, which may include generators and associated transfer switches. These systems are essential in buildings such as hospitals, fire stations, and other facilities where continued operation during a power interruption is vital for safety and functioning.

The other options, while important in their respective areas, do not pertain to the subject of Article 700. Optional Standby Systems, found in Article 701, deal with non-essential loads and are not as crucial as emergency systems. Similarly, Transformers and Transformer Vaults, covered under Article 450, focus on the installation and management of transformers, while Solar Photovoltaic Systems, addressed in Article 690, involve the requirements for solar energy systems. Each of these articles covers specific topics relevant to electrical installations but does not encompass the focused subject matter of emergency power systems like Article 700 does.