In the past three editions of the National Electrical Code (2014, 2017 and 2020), we have seen major changes in the requirements for electrical systems in healthcare facilities. In the 2014 NEC, the reference to requirements in Article 700 were removed from the critical branch and limited to only the life safety branch. This change occurred due to an NFPA Standards Council decision during the 2012 NFPA 99 (Health Care Facilities Code) cycle that the selective coordination requirements in 700.28 for emergency systems were not installation requirements but were, in fact, performance requirements.
Since selective coordination was a performance requirement and, under the jurisdiction of NFPA 99, the critical branch of healthcare facilities no longer referenced Article 700, a new 517.30(G) was inserted into the 2014 NEC that essentially required overcurrent protective devices serving the essential electrical system to be coordinated for the period of time that a fault duration extends beyond 0.1 second. The modifications in all three editions also changed the patient care spaces to category spaces, such as Category 1 for critical care, Category 2 for general care, Category 3 for basic care and Category 4 for support space.
For the 2017 NEC, fuel cell systems, a new alternative source of power, was added to 517.30(B)(2) for essential electrical systems for healthcare facilities. Fuel cell systems are covered in Article 692 with three definitions: fuel cells, fuel cell systems and “interactive (fuel cell) systems.”
A fuel cell is defined as “an electrochemical system that consumes fuel to produce an electric current. In such cells, the main chemical reaction used for producing electric power is not combustion.”
A fuel cell system is defined as “the complete aggregate of equipment used to convert chemical fuel into usable electricity and typically consisting of a reformer, stack, power inverter, and auxiliary equipment.”
An interactive fuel cell system is “a fuel cell system that operates in parallel with and may deliver power to an electrical production and distribution network. For the purpose of this definition, an energy storage subsystem of a fuel cell system, such as a battery, is not another electrical production source.”
This addition of fuel cell systems to the requirements in 517.30 for essential electrical systems for healthcare systems was a total surprise to many professionals in the healthcare industry since generators have been the main alternative power source for many years. NASA has used fuel cell systems in the space program since the mid-1960s, so there is no reason not to use these systems for healthcare facilities.
Primarily, a fuel cell system is an electrochemical cell that uses a fuel source (typically hydrocarbons such as natural gas), separating hydrogen ions (commonly called protons) and electrons from the rest of the molecule through an oxidation reaction. The hydrogen ions (protons) flow from an anode to a cathode through an electrolyte, while electrons flow from the anode to the cathode through an external circuit. This process converts the chemical energy into electrical energy.
Once fuel cell systems were added as a new source of power for healthcare essential systems in the 2017 NEC, the door was open for batteries as a new 517.30(B)(3) in the 2020 NEC, along with an informational note referencing NFPA 111, Standard on Stored Electrical Energy Emergency and Standby Power Systems.
The scope statement in Section 1.1.1 of NFPA 111 is as follows: “This standard shall cover performance requirements for stored electrical energy power supply systems (SEPSS) providing an alternate source of electrical power in buildings and facilities in the event that the normal electrical power source fails.”
Section 1.1.4(6) further states that an SEPSS cannot supply an uninterruptible power system since this would constitute a battery storage system supplying a battery storage system. Based on 5.1.1 in NFPA 111, these energy storage system batteries must have a construction and chemical composition suitable for standby, float service operation and consist of one of the following: (1) lead-acid batteries, (2) nickel-cadmium batteries, (3) nickel-metal hydride batteries or (4) lithium-ion batteries.
Float service operation means the battery will maintain the full charge without boiling out the electrolyte or overcharging the battery. The installation for these systems requires vented batteries such as lead acid, nickel-cadmium or nickel-metal hydride batteries to be installed in a room or rooms dedicated to the batteries and associated equipment with approved ventilation, mounted on open racks. Sealed and valve-regulated batteries shall be permitted in dedicated rooms in open racks, listed battery cabinets or energy storage system cabinets.
Obviously, generators burn fuel and are not as environmentally acceptable as a battery system would be. These battery systems, as now permitted in a healthcare facility, are much more sophisticated systems and will obviously need more maintenance than most battery systems in the past to be as reliable as generators.