google-site-verification: googleac31132f3d1837d9.html

Blog Post Content

Compliance News: Upcoming NFPA 110 Change- Guidance for Rotating Starting ATSs

| David Stymiest

In its June 3, 2015 issue of the NFPA TODAY blog, (also in the June 5, 2015 NFPA conference blog post), NFPA stated that 27 standards in the Annual 2015 revision cycle, including the new NFPA 110, were issued by the NFPA Standards Council on May 26, 2015 as Consent Standards. The new NFPA 110 edition will become NFPA 110-2016.

Anyone can access the next edition’s public development process records online at NFPA 110 under the NEXT EDITION tab.  The First Draft Report indicates the changes approved by the NFPA Standards Council since there were no second draft changes for NFPA 110.  The Second Draft Report simply includes the final language.

Some of the changes in this new NFPA 110 edition can provide the guidance sought by hospital facility managers for years.  This article discusses one such change – guidance for rotating starting automatic transfer switches (ATSs).

The issue of rotating starting ATSs for monthly Emergency Power Supply System (EPSS) test initiation purposes has been a topic of conversation for years.  Many hospitals already rotate their starting ATSs although there are many different approaches. I believe it is a best practice, and some AHJ surveyors have even asked hospitals during surveys if they are rotating their starting ATSs although that practice is not presently a requirement.

New paragraph in NFPA 110-2016 will state “Where multiple ATSs are used as part of an EPSS, the monthly test initiating ATSs shall be rotated to verify the starting function on each ATS.”  This is a new requirement.

As further guidance, new Annex paragraph A. (which is not mandatory but provides the guidance many organizations have requested) will state “The intent is to verify the starting function from each ATS to the EPS by rotating the ATS that initiates the cold engine start of the monthly test. For example, if the facility has 37 ATSs, it can take more than 3 years to verify the starting function of the ATSs. Consideration should be given to ATS criticality. Once the testing cycle is completed, in subsequent years the testing order can be modified to reflect changes to the EPSS.

The 2016 edition of NFPA 110 is not expected to be enforced on a national basis for years.  The 2010 edition, referenced by NFPA 101-2012 and NFPA 99-2012, is expected to become the next nationally-enforced edition if and when CMS adopts the 2012 Life Safety Code®.  State and local AHJs often enforce a more recent edition of NFPA 101 (and/or NFPA 110 in some cases) more frequently than CMS does.

NFPA 101 requires that emergency generators and standby power systems be installed, tested and maintained in accordance with NFPA 110.  Starting in the 2010 edition, NFPA 110 paragraph 1.3 Application states that “This document applies to new installations of EPSSs, except that the requirements of Chapter 8 shall apply to new and existing systems.”  Whenever a state or local AHJ enforces NFPA 110-2016 either directly or by mandatory reference from another standard such as NFPA 101, the paragraph requirement mentioned above is likely to become mandatory for testing affected existing EPSSs.

Regardless of the timetable for national, state or local adoptions, the recommendations of new Annex paragraph A. stated above still represent the best answer currently available to many previous questions.

Although the concept discussed below is NOT mentioned within the 2016 edition of NFPA 110, facility managers of large EPSS installations might also consider determining where they have common engine start circuit wiring serving a group of ATSs by location.  Rotating the specific engine start circuit wiring loops in the following type of sequence could also have the additional impact of verifying the integrity of a different multi-ATS engine start circuit wire each month:

  • Life Safety Branch ATS in Room A
  • Life Safety Branch ATS in Room B
  • Life Safety Branch ATS in Room C
  • Critical Branch ATS in Room A
  • Critical Branch ATS in Room B
  • Critical Branch ATS in Room C
  • And so on through the remainder of the ATSs.

NFPA Disclaimer: Although the writer is Chairman of the NFPA Technical Committee on Emergency Power Supplies, which is responsible for NFPA 110 and 111, the views and opinions expressed in this article are purely those of the speaker and shall not be considered the official position of NFPA or any of its Technical Committees and shall not be considered to be, nor be relied upon as, a Formal Interpretation. Readers are encouraged to refer to the entire texts of all referenced documents.

You may contact the writer at if you have questions on this content.