11.5 Health Care Facilities — Article 517
Key Takeaways
- NEC 517.13 requires redundant grounding in patient care spaces: a metal raceway or cable armor qualifying as an equipment grounding conductor under 250.118, plus a separate insulated copper equipment grounding conductor.
- NEC 517.18(B) requires a minimum of eight receptacles at each patient bed location in a general care space, and 517.19(B)(1) requires a minimum of fourteen at each patient bed location in a critical care space.
- NEC 517.19(A) requires critical care patient bed locations to be supplied by at least two branch circuits, one or more from the critical branch and one or more from a different distribution system.
- NEC 517.30 divides the essential electrical system of a hospital into the life safety branch, the critical branch, and the equipment branch, with the life safety and critical branches forming the emergency system.
- NEC 517.20 requires wet procedure locations to be protected by ground-fault circuit interrupters or by an isolated power system, with GFCI protection not permitted where interruption of power cannot be tolerated.
Why Health Care Is Different
Two conditions drive Article 517. First, patients may be unable to react or move away from an electrical hazard. Second, patients may be electrically susceptible — with a conductive path such as a catheter or intracardiac lead bypassing the skin's natural resistance, currents far below the perception threshold for a healthy person can cause ventricular fibrillation.
The Code's response is redundancy in the grounding path and very tight limits on potential differences between exposed conductive surfaces near a patient.
Key Definitions — 517.2
| Term | Meaning |
|---|---|
| Patient Care Space | Any space of a health care facility wherein patients are intended to be examined or treated. Categorized as Category 1, 2, 3, or 4 spaces |
| Category 1 Space (critical care) | A space in which failure of equipment or a system is likely to cause major injury or death of patients, staff, or visitors |
| Category 2 Space (general care) | A space in which failure of equipment or a system is likely to cause minor injury to patients, staff, or visitors |
| Category 3 Space (basic care) | A space in which failure of equipment or a system is not likely to cause injury but can cause discomfort |
| Category 4 Space (support) | A space in which failure of equipment or a system is not likely to have a physical impact on patient care |
| Wet Procedure Location | The area in a patient care space where a procedure is performed that is normally subject to wet conditions while patients are present |
| Patient Care Vicinity | A space within a patient care space extending 1.8 m (6 ft) beyond the normal location of the bed, chair, table, treadmill, or other device that supports the patient, and extending vertically to 2.3 m (7 ft 6 in.) above the floor |
Wiring Methods and Redundant Grounding — 517.13
517.13 Grounding of Receptacles and Fixed Electrical Equipment in Patient Care Spaces. Wiring in patient care spaces shall comply with 517.13(A) and (B).
(A) Wiring Methods. All branch circuits serving patient care spaces shall be provided with an effective ground-fault current path by installation in a metal raceway system or a cable having a metallic armor or sheath assembly. The metal raceway system, or metallic cable armor or sheath assembly, shall itself qualify as an equipment grounding conductor in accordance with 250.118.
(B) Insulated Equipment Grounding Conductor. The following shall be directly connected to an insulated copper equipment grounding conductor that is installed with the branch-circuit conductors in the wiring methods as provided in 517.13(A):
- The grounding terminals of all receptacles other than isolated ground receptacles;
- Metal outlet boxes, metal device boxes, or metal enclosures;
- All non-current-carrying conductive surfaces of fixed electrical equipment likely to become energized that are subject to personal contact, operating at over 100 volts.
This is the redundant grounding requirement. Two independent paths are required: the metallic raceway or armor, and a separate insulated copper wire. Neither alone satisfies 517.13.
Because 517.13(A) requires the raceway or armor to qualify under 250.118, the practical implications are:
- PVC, ENT, and liquidtight flexible nonmetallic conduit do not qualify for patient care space branch circuits.
- Standard interlocked-armor MC cable does not qualify, because its armor is not listed as an equipment grounding conductor. Health care facility MC cable (MC-HCF) with a bare aluminum grounding/bonding conductor in continuous contact with the armor does qualify, as does Type AC cable per 250.118(8).
- FMC qualifies only within the 250.118(5) limits of 6 feet and 20 amperes.
517.13(B) Exception No. 1 exempts luminaires more than 2.3 m (7 ft 6 in.) above the floor and switches located outside the patient care vicinity from the insulated equipment grounding conductor requirement.
Receptacle Requirements
517.18(A) General Care Spaces — Patient Bed Location Branch Circuits. Each patient bed location shall be supplied by at least two branch circuits, one or more from the normal system and one or more from an emergency system. At least one branch circuit from the emergency system shall supply an outlet or outlets only at that patient bed location. All branch circuits from the normal system shall originate in the same panelboard.
517.18(B) Patient Bed Location Receptacles. Each patient bed location shall be provided with a minimum of eight receptacles. They shall be permitted to be of the single, duplex, or quadruplex type or any combination of the three. All receptacles shall be listed hospital grade and so identified.
517.18(C) Pediatric Locations. Receptacles located within the rooms, bathrooms, playrooms, activity rooms, and patient care spaces of designated pediatric locations shall be listed tamper resistant or shall employ a listed tamper-resistant cover.
517.19(A) Critical Care Spaces — Patient Bed Location Branch Circuits. Each patient bed location shall be supplied by at least two branch circuits, one or more from the critical branch and one or more from the normal system or from a different transfer switch of the emergency system. At least one branch circuit from the critical branch shall supply an outlet or outlets only at that bed location. All branch circuits from the normal system shall be from a single panelboard. Critical branch receptacles shall be identified and shall also indicate the panelboard and branch-circuit number supplying them.
517.19(B)(1) Patient Bed Location Receptacles. Each patient bed location shall be provided with a minimum of fourteen receptacles, at least one of which shall be connected to either of the following: the normal system branch circuit required in 517.19(A), or a critical branch circuit supplied by a different transfer switch than the other receptacles at the same location.
517.19(C) Operating Room Receptacles. Each operating room shall be provided with a minimum of 36 receptacles, at least 12 of which shall be connected to either the normal system branch circuit or a critical branch circuit supplied by a different transfer switch.
The three numbers to memorize are 8 for general care, 14 for critical care, and 36 for operating rooms.
517.19(D) Patient Care Vicinity Grounding and Bonding. A patient equipment grounding point, comprising one or more grounding terminals or jacks, shall be permitted in the patient care vicinity. Where the patient equipment grounding point is supplied, each patient equipment grounding point shall be connected to the reference grounding point by means of an insulated copper conductor.
517.21 Ground-Fault Circuit-Interrupter Protection for Personnel. GFCI protection shall not be required for receptacles installed in those critical care spaces where the toilet and basin are installed within the patient room.
Wet Procedure Locations — 517.20
(A) Protection. Wet procedure locations shall be provided with special protection against electric shock by one of the following means:
- Where interruption of power under fault conditions can be tolerated, by a ground-fault circuit interrupter;
- Where interruption of power cannot be tolerated, by an isolated power system.
Operating rooms are considered wet procedure locations unless a risk assessment conducted by the health care governing body determines otherwise.
517.160 Isolated Power Systems requires each isolated power circuit to be controlled by a switch that has a disconnecting pole in each isolated circuit conductor, requires the isolated circuit conductors to be identified — orange with a distinctive colored stripe for isolated conductor No. 1 and brown with a distinctive colored stripe for No. 2 — and requires a line isolation monitor that indicates possible leakage or fault currents. The monitor shall be designed so that a green signal lamp is visible while the system is adequately isolated, and a red signal lamp and audible warning signal are energized when the total hazard current reaches a threshold value of 5 milliamperes under nominal line voltage conditions.
The Essential Electrical System — Part III
517.30 Essential Electrical Systems for Hospitals. The essential electrical system shall comprise a system of feeders and branch circuits meeting the requirements of Article 700, except as amended by Article 517, and shall be divided into:
| Branch | Serves | Transfer time |
|---|---|---|
| Life Safety Branch | Illumination of means of egress, exit signs, alarm and alerting systems, communications systems, generator set and transfer switch locations, elevator lighting and controls, automatic doors | 10 seconds |
| Critical Branch | Task illumination, fixed equipment, select receptacles, and select power circuits serving patient care areas and functions related to patient care | 10 seconds |
| Equipment Branch | Major electrical equipment necessary for patient care and basic hospital operation — heating, ventilating, elevators, sterilizers, and similar | Delayed automatic or manual connection |
The life safety branch and the critical branch together constitute the emergency system, which must be connected to the alternate power source within 10 seconds. The equipment branch is arranged for delayed automatic connection or delayed manual connection.
517.31(C)(3) Separation from Other Circuits. The life safety branch and critical branch of the emergency system shall be kept entirely independent of all other wiring and equipment and shall not enter the same raceways, boxes, or cabinets with each other or other wiring, with listed exceptions including transfer equipment enclosures and luminaires supplied from two sources.
517.30(G) Coordination. Overcurrent protective devices serving the essential electrical system shall be coordinated for the period of time that a fault's duration extends beyond 0.1 second, with exceptions for devices between transformer primary and secondary, and for devices of the same size in series.
517.34 Essential Electrical Systems for Nursing Homes and Limited Care Facilities and 517.45 Essential Electrical Systems for Other Health Care Facilities apply parallel but reduced requirements.
Alaska Application
Alaska's health care network runs from the Alaska Native Medical Center and regional hospitals down to village clinics operated under tribal health organizations. The Article 517 rules apply by space category and function, not by facility size. A village clinic examination room is a patient care space and requires 517.13 redundant grounding and hospital-grade receptacles at the patient bed location just as a large hospital does, even though it will not have a full three-branch essential electrical system under 517.30. 517.45 governs the essential electrical system requirements for those other health care facilities.
The practical wiring consequence for a remote Alaska clinic project is that the common cost-saving wiring methods — PVC and ordinary interlocked-armor MC — are not permitted for patient care space branch circuits. Plan for EMT with an insulated copper equipment grounding conductor, or health care facility MC cable.
What does NEC 517.13 require for branch circuits serving patient care spaces?
What is the minimum number of receptacles required at each patient bed location in a critical care space under NEC 517.19(B)(1)?
Which two branches of a hospital essential electrical system together constitute the emergency system that must be restored within 10 seconds?
A wet procedure location in a hospital cannot tolerate interruption of power under fault conditions. What protection does NEC 517.20(A) require?