NFPA 110 – Standard for Emergency and Standby Power Systems

This edition of NFPA 110, Standard for Emergency and Standby Power Systems was prepared by the Technical Committee on Emergency Power Supplies and released by the Correlating Committee on National Electrical Code’. It was issued by the Standards Council on March 18, 2021, with an
date of April 8, 2021, and supersedes all previous editions.
This edition ofNFPA 1 10 was approved as an American National Standard on April 8, 2021.

The Technical Committee on Emergency Power Supplies was organized in 1976 by NFPA in recognition of the demand for viable guidelines for the assembly, installation, and performance of electrical power systems used to supply critical and essential needs during outages of the primary
power source. The intent was to establish the equipment requirements necessary to achieve an on-site auxiliary electrical power source suitable to the needs of the applicable requirements and user criteria.

In 1979, the committee’s report proposing the adoption of NFPA 110 was published but withdrawn because of issues involving the scope of the committee. In 1981, a revised report was returned to the committee to resolve differences with other NFPA documents.

At the 1982 NFPA Fall Meeting, the committee’s report was adopted as a tentative standard (NFPA 110 T-1983) to expose the document to public review.
NFPA 110 was formally adopted as a standard at the 1984 NFPA Fall Meeting and designated the 1985 edition, which clarified scope statements, prototype testing, battery and bypass-isolation switch requirements, and revised maintenance requirements.

The 1988 edition included several new definitions and fürther clarified transfer switch and installation testing requirements.
The 1993 edition reflected the adoption of NFPA 111, Standard on Stored Electrical Energy Emergency and Standby Power Systems, a basic requirement for one-step loading for all prime movers, an update on battery technology, restrictions on unnecessary transferring of loads, and the need for battery maintenance.