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Compliance News: Revisiting the Three-Year Four-Hour EPSS Load Test Requirements from NFPA 110-2010

| David Stymiest

Now that CMS has adopted the 2012 Life Safety Code™ and 2012 Health Care Facilities Code, CMS is surveying for compliance with NFPA 110-2010.  NFPA 110-2010 has very specific requirements for the 3-year 4-hour EPSS load test, and many hospitals may not be complying with those requirements.

From NFPA 101-2012® Life Safety Code® [referencing NFPA 110-2010] Emergency generators and standby power systems shall be installed, tested, and maintained in accordance with NFPA 110, Standard for Emergency and Standby Power Systems. Emergency generators providing power to emergency lighting systems shall be installed, tested, and maintained in accordance with NFPA 110, Standard for Emergency and Standby Power Systems.

From NFPA 99-2012 Health Care Facilities Code [referencing NFPA 110-2010] Maintenance [author’s note: of the Alternate Power Source & transfer switches] “shall be performed in accordance with NFPA 110, Standard for Emergency and Standby Power Systems, Chapter 8.” Inspection and Testing. Criteria, conditions, and personnel requirements shall be in accordance with through … “Generator sets serving essential electrical systems shall be tested in accordance with NFPA 110, Standard for Emergency and Standby Power Systems, Chapter 8.” Emergency Generators and Stand by Power Systems.  Emergency generators and standby power systems, where required for compliance with this code, shall be installed, tested, and maintained in accordance with NFPA 110

From CMS K-tag # K-918 [referencing NFPA 110-2010]

Electrical Systems – Essential Electric System Maintenance and Testing The generator or other alternate power source and associated equipment is capable of supplying service within 10 seconds. If the 10-second criterion is not met during the monthly test, a process shall be provided to annually confirm this capability for the life safety and critical branches. Maintenance and testing of the generator and transfer switches are performed in accordance with NFPA 110. Generator sets are inspected weekly, exercised under load 30 minutes 12 times a year in 20-40 day intervals, and exercised once every 36 months for 4 continuous hours. Scheduled test under load conditions include a complete simulated cold start and automatic or manual transfer of all EES loads, and are conducted by competent personnel. Maintenance and testing of stored energy power sources (Type 3 EES) are in accordance with NFPA 111. Main and feeder circuit breakers are inspected annually, and a program for periodically exercising the components is established according to manufacturer requirements. Written records of maintenance and testing are maintained and readily available. EES electrical panels and circuits are marked and readily identifiable. Minimizing the possibility of damage of the emergency power source is a design consideration for new installations. 6.4.4, 6.5.4, 6.6.4 (NFPA 99), NFPA 110, NFPA 111, 700.10 (NFPA 70)

From the CMS Emergency Preparedness Final Rule [referencing NFPA 110-2010]

482.15 (e) (2) Emergency generator inspection and testing. The hospital must implement the emergency power system inspection, testing, and maintenance requirements found in the Health Care Facilities Code, NFPA 110, and Life Safety Code.

Note that there are similar paragraphs (not copied here) for Long Term Care (LTC) Facilities and Critical Access Hospitals (CAH).  

Below are a few excerpts from section 8.4.9 of NFPA 110-2010, which is the section covering the 3-year 4-hour load test: The test shall be initiated by operating at least one transfer switch test function and then by operating the test function of all remaining ATSs, or initiated by opening all switches or breakers supplying normal power to all ATSs that are part of the EPSS being tested.  [Author’s comment: This paragraph is not describing a load bank-only load test, which is what many hospitals are presently doing.] A power interruption to non-EPSS loads shall not be required.  [Author’s comment: It is not necessary to shut off normal power for this test.] The minimum load for this lest shall be as specified in,, or For a diesel-powered EPS, loading shall be not less than 30 percent of the nameplate kW rating of the EPS. A supplemental load bank shall be permitted to be used to meet or exceed the 30 percent requirement. For a diesel-powered EPS, loading shall be that which maintains the minimum exhaust gas temperatures as recommended by the manufacturer. For spark-ignited EPSs, loading shall be the available EPSS load. [Author’s comment: And finally, and provide the requirements for combining this 3-year 4-hour load test with other load tests.]

Hospitals that are presently doing a load bank-only 3-year 4-hour load test may want to revisit their current practices in light of the requirements stated above.

NFPA Disclaimer: Although the author is a primary voting member and was the 10-year 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 message are purely those of the author 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.  Interested parties can review copies of NFPA 110 at

Questions related to this article may be directed to the author, David Stymiest PE CHFM CHSP FASHE at