Which NEC article covers legally required standby systems?

• A. Article 701
• B. Article 700
• C. Article 430
• D. Article 600

Answer: (A)

Legally required standby systems are the backup-power setups required by law or by the authority having jurisdiction to keep certain building services operating when normal power is lost. The NEC treats these as a distinct category and has a dedicated article that specifies how such systems must be designed, installed, and maintained, including how the standby source is connected and how automatic transfer occurs. This category sits separately from emergency systems, which power life-safety loads, and from optional standby systems, which back up discretionary loads chosen by the owner. The other topics addressed by the remaining options cover different parts of electrical installations and are not about legally required standby arrangements.