In this episode of “EC&M Tech Talks,” Randy Barnett, a journeyman electrician, inspector, author, trainer, and electrical safety expert, reviews the installation requirements for generators in Art. 445 of the National Electrical Code. However, there is much more in the NEC to installing a generator than just what is in Art. 445. The application of the generator system must be considered. Chapter 7 of the NEC supplements the information found in Art. 445.
Article 700 addresses emergency light and power systems. When designated as such by the authority having jurisdiction (AHJ), these systems must begin delivering power within 10 seconds after a loss of normal power. The failure of these systems is considered a hazard to human life and health. Article 701 addresses legally required systems. These systems are considered less critical than article 700 systems and have 60 seconds to begin delivering power. Article 700 requirements will be the most stringent. For example, the conductors for emergency power systems must be installed independently of the normal lighting and power circuits for a facility. Legally required standby system conductors may occupy the same raceway as other conductors.
Article 702 of the NEC provides supplemental requirements for optional standby systems. These installations may only be needed for human comfort or, in some cases, in facilities where it is desired to conduct a normal shutdown of systems or processes in the event of a loss of power.
The NFPA 110, Standard for Emergency and Standby Power Systems, provides details far beyond NEC information regarding the installation, operation and maintenance and emergency and legally required power systems.
