701-Legally Required Standby Systems
I. General
701.1 Scope. The provisions of this article apply to the electrical safety of the installation, operation, and maintenance of legally required standby systems consisting of circuits and equipment intended to supply, distribute, and control electricity to required facilities for illumination or power, or both, when the normal electrical supply or system is interrupted.
The systems covered by this article consist only of those that are permanently installed in their entirety, including the power source.