The NFPA 99 Health Care Facilities Code establishes the minimum criteria for the installation, performance, and operation of a wide range of systems and equipment in health care facilities to ensure the safety of patients, staff, and the public from electrical failures, fires, and other hazards.
NFPA 99 treats emergency generators as part of an essential electrical system (EES), which is defined as, “A system comprised of alternate sources of power and all connected distribution systems and ancillary equipment, designed to ensure continuity of electrical power to designated areas and functions of a health care facility during disruption of normal power sources, and also to minimize disruption within internal wiring systems.
What is an essential electrical system (EES)?
The terminology used for backup (emergency and standby) power systems in health care facilities is different than other facilities. It is designated as the “essential electrical system” per NFPA 70: National Electrical Code (NEC) Article 517, which is consistent with the terminology and requirements stated in NFPA 99: Health Care Facilities Code.
The essential electrical system (EES) requirements can be found in NFPA 99, Chapter 6; these describe two different EES requirements (Type 1 or 2) that correlate to different risk categories (Categories 1 through 4) defined in Chapter 4. The Category 1 spaces require EES Type 1 service while Category 2 spaces require EES Type 2 service. There are very few differences between EES Types 1 and 2, other than their power-distribution system.
Hospitals, for the most part, fall under the risk Category 1, where equipment and systems are expected to work and be available at all times, and their failure is likely to cause major injury or death to patients, staff, or visitors. On the other hand, the Category 2 spaces are areas of the hospital where failure of equipment or a system is likely to cause minor injury to patients, staff, or visitors, but no risk to life.
Emergency generators that are installed shall be tested and maintained in accordance with NFPA 110, Standard for Emergency and Standby Power Systems.
How much fuel can a health care facility have stored on site for running a generator?
There are several factors to consider when determining how much fuel a facility should have stored on site for running a generator.
If the generator serves as a component of an Essential Electrical System (EES) as required for critical care rooms and general care rooms by NFPA 99 (2012 edition) Health Care Facilities Code, Chapter 6, then the licensing authority (typically the state health department) should be consulted for applicable requirements.
“Basic Care” patient rooms in facilities, such as those used for inpatient behavioral health, do not require an EES. However, in many of these facilities, the generator is the alternate source of power for the illumination of the means of egress, emergency (task) lighting, exit lights, and/or the fire alarm system. NFPA 101 Life Safety Code requires these all to have a minimum duration of 1-1/2 hours (Class 1.5) (which may also be from a battery source).
The Joint Commission Emergency Management Standard EM.02.02.09 EP 5 requires that hospitals identify an alternative means for providing “fuel required for building operations, generators, and essential transport services that the hospital would typically provide.” The facility should assess how it would be affected if outside emergency support could not be obtained for 96 hours. This does not mean that they need to have 96 hours worth of fuel on site. The plan could include memoranda of understanding (MOUs) with suppliers to replenish fuel as needed during the emergency period. Additionally, the plan could be to operate without normal branch of power to reduce fuel consumption, to extend run-time of the available fuel. If the generator is used as the backup power source for the life safety branch of the electrical system, the facility should have enough fuel to run the generator for a least 1-1/2 hours for as long as the building is occupied.