How to use NFPA 70 for patient spaces in health care facilities
When designing health care facilities, electrical engineers need to consult and comply with myriad different standards and regulations to ensure a safe and code-compliant design
Learning Objectives
- Understand the difference in NFPA 70: National Electrical Code (NEC) requirements for hospital, outpatient and nursing home facilities.
- Define the NEC requirements for various patient care spaces within health care facilities.
- Learn the difference between Type 1 and Type 2 essential electrical systems and where each is required.
NEC insights
- NFPA 70: National Electrical Code (NEC) outlines rigorous standards for electrical installations in health care facilities and hospitals, ensuring the reliability and safety of critical systems like life support and emergency power.
- Compliance with NEC in these environments is crucial, as it directly impacts patient safety and the continuous operation of essential medical equipment.
- In this article, we will explore the various challenges within health care project design and how to navigate the NEC to ensure electrical safety and reliability within your designs.
The primary code book that an electrical engineer will reference on any given design project is NFPA 70: National Electrical Code (NEC). Health care facility design requires review and compliance with many codes, standards and regulations, however, compliance specifically with the NEC is a complex and important part of the design.
Article 517 within the NEC is dedicated to the design of health care facilities and references many of the other relevant codes and regulations, including both NFPA 99: Health Care Facilities Code and NFPA 101: Life Safety Code. Each of these code books have sections within them dedicated to electrical design, but also cover the more general requirements of health care facilities and life safety systems in greater detail.
While it is important to refer to these codes directly, the NEC is a great starting point that incorporates some of the most important electrical requirements within those codes into Article 517. Direct references to these code books can be found throughout Article 517 by the bracketed reference numbers following sections of text. Article 517 contains many subdivisions that indicate the requirements for specific types of health care facilities and equipment.
To determine which portions of Article 517 need to be followed, it is important to first understand the facility type being designed and what patient care services it will provide.
Determining health care facility requirements
The NEC defines health care facilities as “buildings, portions of buildings or mobile enclosures in which human medical, dental, psychiatric, nursing, obstetrical or surgical care is provided.” The type of facility, from hospitals to outpatient medical office buildings to nursing homes, will determine which requirements within the NEC need to be met. Areas such as business offices, corridors, waiting rooms and the like in outpatient facilities as well as immunization, psychiatry/psychotherapy offices and optometry centers do not fall under the umbrella of Article 517.
Code requirements ranging from basic wiring device locations and quantities to essential electrical system functions will be dictated by the type of facility and which patient care spaces are provided. It is essential to coordinate with both the architect and owner to understand what types of patient care will be performed, ensuring the correct set of requirements within the NEC are followed, to prevent the over or under, designing of the facility.
Inpatient facilities — hospitals: When thinking about what types of buildings are classified as health care facilities, hospitals are typically the first to come to mind. The NEC defines hospitals as “buildings or portions thereof used on a 24-hour basis for the medical, psychiatric, obstetrical or surgical care of four or more inpatients.” Hospitals will typically include several inpatient rooms, operating rooms, intensive care units and the like, requiring a more robust electrical system in comparison to other health care facilities.
Outpatient facilities — medical office buildings/ambulatory surgical centers: Outpatient facilities can have a wide range of different requirements depending on what types of services are being provided. Facilities such as clinics and dental offices have different requirements from hospitals due to the lower risk associated with power failures. The NEC defines medical offices as “buildings or part thereof in which examinations and minor treatments/procedures are performed under the continuous supervision of a medical professional.” The expectation within these facilities is that any sedation would be minimal and patients are not required to stay overnight.
Ambulatory surgical centers fall in the area between hospitals and medical clinics. These facilities are typically equipped with operating rooms or procedure rooms that require anesthetizing patients, but on an outpatient basis. These facilities are not equipped with inpatient rooms typical to hospitals.
Nursing homes: Nursing homes, which provide long-term care for residents, have specific electrical requirements to ensure the safety and comfort of their occupants. Nursing homes can range from independent living facilities to assisted living facilities, each requiring a unique set of requirements. Independent living facilities tend to have similar electrical requirements to medical office buildings but facilities that require more assistance become more involved if certain patient care spaces, such as dialysis rooms or memory care areas, are included in their design.
Patient care space requirements: Determining the type of facility will provide a foundation for what codes requirements will be involved in the design. The next step is to make sure the design meets the requirements for each individual type of patient care space included within the facility. The NFPA defines a patient care space as “any space of a health care facility wherein patients are intended to be examined or treated.” These spaces can be further broken down into categories, defined by the type of patient care provided within each space (see Table 1).
Determining which patient care spaces will be included in the design requires coordination with both the architect and owner of the facility to ensure the correct electrical system is provided. It is important to note that the distinction of each space type should be provided by the health care facility’s governing body. While the NEC provides examples of each category, it is up to the health care facility to review and designate each space with a category based on the type of patient care anticipated.
This is particularly important to confirm in the design of imaging rooms as these spaces can span from Category 1, such as image-guided open surgical procedures, to Category 3, such as diagnostic imaging like mammography and ultrasounds.
Navigating NEC Article 517 for health care designs
Once the type of health care facility and patient care spaces being designed are confirmed, it is possible to determine the requirements of the essential electrical system (EES) for the facility as well as the more granular requirements of each patient care space. Part III of Article 517 is dedicated to the requirements of each type of EES and what they can serve within the health care facility. Part II covers wiring and protection requirements, along with specific patient care space requirements, such as receptacle quantities and branch circuits. When starting out a design, it can be helpful to refer to Part III first to ensure the overall electrical system requirements are being met.
Essential power selection: Type 1 versus Type 2: The NEC defines an essential power system as “a system comprised of alternate power sources 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 the internal wiring system.”
These systems are designed to provide a reliable power source to maintain patient care and safety by ensuring vital equipment and systems remain operational during normal utility power outages. The two major portions of an EES are the emergency power supply (EPS) and its associated emergency power supply system (EPSS). As defined by the NEC, the EPS is the source(s) of electric power for the EPSS, while the EPSS consists of all conductors, disconnecting means, overcurrent protection devices, transfer switches and associated controls/support devices up to and including the load terminals of the transfer equipment. These, along with the panelboards, branch circuits and devices downstream, make up the facility’s EES.
Type 1 essential electrical systems are the most stringent and are required in environments where a power failure could result in loss of life or serious injury. Articles 517.29 through 517.35 of the NEC are dedicated to the requirements for Type 1 EES. These systems are required in all facilities with Category 1 patient care spaces, typically hospitals and ambulatory surgical centers, but may also be used to serve Category 2, 3 and 4 spaces.
Every Type 1 EES is required to have at least two independent sources of power, a normal source that generally supplies the entire electrical system and one or more alternate sources of power, such as an emergency generator, fuel cell or battery system. The components should be in such a way to minimize any interruptions caused by natural forces and all feeders are required to be physically separated from the normal power feeders to prevent possible simultaneous interruption.
Type 1 EES are separated into three power branches (see Figure 3):
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Life safety branch: This branch supplies power to systems that are essential for life safety, such as exit signs, egress lighting, alarm and alerting systems such as fire alarm and medical gas alarm, communication systems required for issuing instructions during emergency conditions, generator set accessories, elevator lighting, control and communication systems and electrically powered egress doors. These systems must remain operational to ensure safe evacuation and emergency response. This branch is required to automatically connect to the EPS within 10 seconds upon loss of normal power.
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Critical branch: This branch powers equipment and systems that are critical to patient care. This includes task lighting, selected receptacles and fixed equipment in critical care areas as well as nurse call and information technology systems. The critical branch ensures that essential medical equipment remains functional during a power outage. In addition to the equipment listed in Article 517.34, the governing body of the facility can determine if any additional equipment is required to be backed up on the critical branch to ensure effective facility operation. While this branch can be flexible based on the facility needs, there are some limitations to motor circuits, allowing only single-phase, fractional horsepower motors to be connected to the system. This branch is required to automatically connect to the EPS within 10 seconds upon loss of normal power.
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Equipment branch: This branch supplies power to systems that are necessary for the overall operation of the facility, such as heating, ventilation and air conditioning systems, elevators and other building systems. While not directly related to patient care, these systems are crucial for maintaining a safe and functional environment. This branch is required to be automatically connected to the EPS at an appropriate time-lag interval following the energizing of both the life safety and critical branches, typically within 60 seconds upon loss of normal power. Depending on the types of equipment served by this branch, manual transfer to the EPS can be an option, as described in Article 517.35(B).
Any equipment that is not served by these three branches can be served by a fourth optional branch of the EES. This branch requires a dedicated transfer switch that should not transfer if doing so would overload the EPS. This branch is also required to be automatically shed upon overloading of the EPS if it had already transferred.
Type 2 essential electrical systems are required in facilities where a critical power branch is not required. These systems are typically found in outpatient clinics, nursing homes and other health care facilities where the risk associated with power failure is lower, as no Category 1 patient care spaces are present. Articles 517.40 through 517.44 of the NEC describe the requirements for Type 2 essential power systems with the main differences from Type 1 systems:
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Facilities that have Category 2 but no Category 1 spaces are required to have a Type 2 EES backing up their utility power. Though they are not required, Type 1 systems can still be used if preferred by the owner of the facility.
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Simplified branches: Unlike Type 1 systems, Type 2 systems are only required to have two separate branches: life safety and equipment power.
The life safety branch of both Type 1 and Type 2 EES needs to comply with the requirements of Article 700 as described and amended in Article 517.26. One requirement worth noting is the temporary source of power for maintenance or repair of the alternate source of power, indicated in Article 700.3(F). To meet this requirement, a permanent connection for a portable generator, sized to serve the life safety branch, must be installed to provide temporary power during periods of maintenance on the permanent EPS.
It is possible to bypass the requirement of a temporary power connection point if a second, permanent alternate energy source is installed that can support the life safety branch. One solution commonly employed at larger health care facilities is to provide paralleled generators in lieu of a single generator when designing the EPS, with one remaining operational while the other is serviced.
For both EES types, separation of each system branch occurs at the transfer switches, per Articles 517.31 and 517.42. In addition to the standard essential power branches, branches may be provided for a fire pump if included in the design and elevator systems if they are not connected to the equipment branch. If the transfer switches are located ahead of an essential power switchboard, each vertical section within the switchboard is required to be separated by a barrier to maintain isolated branches. If the essential power switchboard is located ahead of the transfer switches, it is not required to have separate, barriered vertical sections for each branch. In instances where the power source is limited to 150 kilovolt amperes (kVA), the separation of the branches can occur after a single automatic transfer switch (ATS), per Articles 517.31(B) and 517.42(B).
Facilities that only have Category 3 and Category 4 spaces are not required to have an EES as part of their design. They are still required to meet emergency egress lighting and fire alarm requirements though, so many owners will opt to install a Type 2 system to accommodate any future needs the facility may have.
Patient care vicinity panelboard requirements: Panelboards that serve patient care vicinities have additional bonding requirements as noted in Article 517.14. The NEC defines a patient care vicinity as “a space, within a location intended for the examination and treatment of patients, extending 1.8 meter (6 feet) beyond the normal location of the bed, chair, table, treadmill or other device that supports the patient during examination and treatment and extending vertically to 2.3 meter (7 feet 6 inches) above the floor.”
Any panelboards serving the same patient care vicinity are required to have their equipment grounding terminal buses connected or connected to the same copper busbar installed in an accessible location by an insulated continuous copper conductor 10 AWG or larger.
Hospital-grade wiring: The term “hospital-grade wiring” is a generalization referring to all wiring that falls under Article 517.13 of the NEC. This article requires all wiring within patient care spaces to be provided with a redundant grounding path. Article 517.13(A) requires the raceway, cable armor or sheath to act as effective ground-fault current path in addition to the green-insulated copper grounding conductor required by Article 517.13(B). The following common wiring methods will typically meet both requirements.
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Cable within electrical metallic tubing (EMT).
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Type AC cable – AC-HCF.
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Type MC cable – MC-HCF.
Standard MC cable and wiring within polyvinyl chloride conduit do not meet the requirements of Article 517.13. The acceptable wiring methods noted above must be used in all patient care spaces within a health care facility. One exception to this rule is the wiring to any light fixtures mounted above 7 feet 6 inches and their associated light switches, should those be located outside the patient care vicinity, as indicated in the “exception” text to Article 517.13.
In that case, it is acceptable to meet the requirements of either 517.13(A) or 517.13(B). Any life safety or critical branch circuits intended to be served by flexible metal sheathed cable must also meet the requirements of Article 517.31(C)(3)(3). If these requirements cannot be met, these circuits should be served by cable within EMT.
Some owners have standards requiring that these wiring methods be used throughout their facilities, even in areas where patient care is not provided. This helps to “future proof” an installation, allowing any existing wiring to be maintained and reused should a nonhealth care space (such as offices, breakrooms, corridors) be reworked into a patient care space.
Hospital-grade receptacles: Hospital-grade receptacles are required to ensure a proper grounding connection when equipment is plugged in within a patient care space. They also require additional pull-force to remove the plugs, helping prevent accidental removal. Unlike hospital-grade wiring, hospital grade receptacles are only required in specific patient care spaces; Category 1 and Category 2. This is noted in Articles 517.18 and 517.19 of the NEC. While these receptacles are not required in every type of patient care space, many health care facilities will require they be installed in all areas of their buildings to help ensure their spaces are code compliant, should the space type change in the future.
Receptacle quantity/branch circuit power requirements: Some patient care spaces have receptacle quantity requirements described in Article 517 of the NEC. The NEC defines a single receptacle as “a single contact device with no other contact device on the same yoke or strap.” The receptacle requirements within Article 517 can be achieved using any combination of single or multireceptacle devices, such as duplex receptacles. Both Category 2 and Category 1 spaces have receptacle quantity and branch circuit requirements indicated in Article 517.18 and 517.19, respectively. Operating rooms are also provided with their own set of requirements as well as wet procedure locations:
- Category 2 Spaces: Per Article 517.18, Category 2 patient care bed locations are required to have a minimum of eight receptacles and two branch circuits; one normal branch and one critical branch. If there are two critical branches served by separate automatic transfer switches, it is permitted to use one branch circuit from each in lieu of a normal branch circuit.
- Category 1 Spaces: Per Article 517.19, Category 1 patient care bed locations are required to have a minimum of 14 receptacles and two branch circuits; one normal branch and one critical branch. If there are two critical branches served by separate automatic transfer switches, it is permitted to use one branch circuit from each in lieu of a normal branch circuit. In addition, one of the critical branches must be dedicated to receptacles at the patient bed location.
- Operating rooms: Per Article 517.19(C), operating rooms are required to have a minimum of 36 receptacles and two (branch circuits; one normal branch and one critical branch. If there are two critical branches served by separate ATS, it is permitted to use one branch circuit from each in lieu of a normal branch circuit. At least 12 but no more than 24 receptacles shall be connected to each of the branch circuits within the room.
- Wet procedure locations: Branch circuits serving wet procedure locations must be provided with ground fault protection to interrupt the power supply or be fed by an isolated power system to mitigate the possible ground fault current to a low value without interrupting the power. Operating rooms will typically fall under this category, but coordination should be done with the facilities governing body to determine if any other patient care space is required to meet these criteria. Selection of either ground fault protected receptacles or isolated power should also be coordinated with the owner, as the loss of power associated with the ground fault protected receptacles can pose a hazard for some critical procedures.
Using the NEC’s framework
In addition to the NEC, FGI Guidelines should be referenced to determine recommended receptacle quantities in the spaces not covered by the NEC. While the FGI Guidelines may not be formally adopted in all states, they are seen as an industry standard for proper health care planning, design and construction and provide recommendations for spaces not formally covered by the NEC.
The implementation of NFPA 70 in health care facilities varies based on the type of facility and the associated patient care services provided. While there are other health care specific codes that must be followed, the NEC provides a framework for many of the patient care spaces that are typical to all health care projects. Understanding the different requirements for each type of facility and patient care space is essential for ensuring the safety and reliability of the electrical systems throughout every health care facility.
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