Ecmweb 8642 Code Apps November16
Ecmweb 8642 Code Apps November16
Ecmweb 8642 Code Apps November16
Ecmweb 8642 Code Apps November16
Ecmweb 8642 Code Apps November16

Critical Code Requirements for Health Care Facilities

Nov. 18, 2016
To keep patients safe, be methodical and thorough with bonding in these installations.

When the NEC speaks of health care facilities, it means places where people are obtaining medical, dental, psychiatric, nursing, obstetrical, or surgical care [517.1]. That doesn’t necessarily mean a hospital, either. Health care facilities include clinics, dental offices, nursing homes, and ambulatory care centers. So this isn’t as straightforward as it might seem. You could easily make the wrong assumptions about the facility.

Suppose you get a project at a four-unit “professional strip mall.” The sign out front lists an architect, a law office, a real estate office, and your customer. She is Dr. Sandra Miller, M.D. Does Art. 517 apply to work done in this building? In your case it might, because you’re working in the unit that the NEC could potentially define as a health care facility. However, Dr. Miller does not see patients at this office. She has hospital privileges at the hospital only a few blocks away. This office is where her assistant handles the appointments, billing, records, and other aspects of Dr. Miller’s practice. Since patients do not receive care in this office, Art. 517 doesn’t apply in this location.

Ryan McVay/Photodisc/Thinkstock

Suppose Dr. Miller provides care for patients at this office, and she is not your customer. You are, instead, working for the building owner. He wants ground-fault protection for the service. That work will affect Dr. Miller’s office. In this case, you must apply selectivity per 517.17(C).

What if your customer is a health spa where, every Friday, a visiting nurse opens a station where members can get a consultation and get blood drawn (a gym on Florida’s east coast caters to senior citizens and provides something similar)? What if it’s another strip mall situation that contains a UPS store and a restaurant, but one occupant provides therapy just for people’s hands (this mall is in Shawnee, Kan.)?

Larger factories and public schools include a nurse’s station. You might walk into a facility that manufactures motors, but if it has a nurse’s station (where nursing care is provided), you’ve now got to consider Art. 517 from that station’s branch circuit all the way to the service.

You can see how important it is to properly characterize the facility. Don’t assume the work has to be in a standalone clinic or hospital for Art. 517 to apply.

Understanding 517’s goal

Though it’s long, Art. 517 can’t anticipate every permutation of every possible installation. You want to conform to its intent. The intent is to minimize electrical hazards by keeping adequately low potential differences between exposed conductive surfaces that are likely to become energized and could be contacted by a patient [517.11].

This is an area where you can easily fall short. The Informational Note following 517.11 is helpful in succeeding here, because it explains some of the challenges of addressing these potential differences.

For example, consider that a conductive path from the patient’s body to some grounded object can be established through instrumentation. Or a patient may accidentally come into contact with a grounded object. These and other scenarios mean you could have sources of electrical currents that run across a person’s body.

Following the Art. 517 requirements includes following the requirements of Chapters 1 through 4, except as modified by Art. 517. But is that enough to ensure a safe installation? No, the Code-Making Panel members can’t foresee everything — nor can even the best engineering team when producing the project’s drawings and specifications. If you’re the installer, you’re in a good position to find and fill any holes in the protection measures.

To prevent Code violations, determine what grounded metallic objects are or will be in that room and where they will be in relation to the patient. Those objects will include both fixed and (likely to be used) portable equipment.

Create a drawing showing these objects and the likely patient locations, noting where distances are “within reach.” Ask the end-users to review your drawing if at all possible. Then use the drawing to keep track of where the current paths for each object have been addressed.

For example, Object 3 has exposed surfaces that might become energized, but you insulate those surfaces. Draw an X through that object. Make sure all of the objects are X’d out. Retain a copy of the final drawing. If there is a problem later on, you can prove you did more than just meet Code or just implement project specifications. But if you take this extra step, you make a problem very unlikely.

Grounding receptacles and fixed equipment

The equipment grounding conductor (EGC) is critical in these facilities, so let’s make sure we understand what it is. Article 100 defines the EGC as “the conductive path(s) that provides a ground-fault current path and connects normally non-current carrying metal parts of equipment together and to the system grounding conductor or to the grounding electrode conductor or both.”

Given that definition, you can avoid confusion by thinking of the EGC as the equipment bonding conductor. It’s part of the bonding system. The bonding system establishes electrical continuity and conductivity between metal parts [100], putting them at the same potential. If you have 0V between two objects, no current will flow.

All branch circuits serving patient care areas must have an effective ground-fault path. To get this path, you must install the circuit in a metal raceway system or a cable having a metallic armor or sheath assembly [517.13(A)]. The raceway or cable you use must qualify as an EGC per 250.118.

When you run that branch circuit, you must also include (inside the raceway or cable) an insulated copper EGC [517.13(B)]. Use this EGC to connect all of the following:

1) The grounding terminals of all receptacles.

2) Metal boxes and enclosures containing receptacles.

3) Noncurrent-carrying conductive surfaces of fixed electrical equipment, operating at more than 100V, if the surface is likely to become energized and is subject to personal contact.

Three exceptions are listed under 517.13(B).

Ground-fault protection

Special ground-fault protection rules apply to any place with critical care or life-support equipment [517.17(A)]. The rules apply to the entire building, where ground-fault protection is provided for the operation of the service disconnect or feeder disconnect.

First, you must have an additional step of ground-fault protection in all next feeder disconnects downstream (toward the load). But don’t install these on the load side of an essential electrical system transfer switch [517.17(B)]. See Art. 517, Part III for the requirements of essential electrical systems.

Your ground-fault protection is going to be overcurrent devices (e.g., fuses or breakers) and current transformers that cause the feeder disconnect to open. Other “equivalent means” of causing that disconnect to open are acceptable, but nail down “equivalent means” with the AHJ before you go that route.

Now comes the tricky part. The ground-fault protection must be fully selective. The feeder device, not the service device, must open when there’s a ground fault on the load side of that feeder [517.17(C)].

Don’t leave this coordination to chance. It’s highly advisable to conduct a formal coordination study. When the equipment is first installed, you must conduct performance tests to prove it works with 100% selectivity [517.17(D)]. You don’t want to still be figuring things out at this stage.

General versus critical care

The requirements for general care [517.18(A) through (C)] are understandably less rigorous than those for critical care [517.19(A) through (H)].

The main difference in the patient bed location requirements is the critical care bed must have at least one branch circuit from the critical branch [517.18/19(A)]. The main difference in the receptacle requirements is the critical care bed must have at least 14 receptacles rather than the eight for general care bed [517.18/19(B)].

For general-care pediatric locations, receptacles must be tamper-resistant or have a tamper-resistant cover [517.18(C)]. 517.19(C) through (H) cover operating room receptacles, grounding point in a patient care vicinity, bonding to the EGC, isolated power systems, and special-purpose receptacle grounding.

So much more

In this discussion, we started at the beginning of Art. 517 and stopped just short of reaching the end of Part II. However, there are seven Parts. The other five pertain to specific types of installations, not health care facilities generally.

Did you notice the main emphasis of Art. 517 is on bonding? Other concerns are also important, but it’s here where so much confusion is possible, and the potential for lethal shock can be eliminated (or not). To avoid confusion or simple oversights, draw out the “system” of metallic objects, and ensure they’re bonded to that EGC. Zero potential means zero current flow means zero electrocutions.              

Lamendola is an electrical consultant located in Merriam, Kan. He can be reached at [email protected].

About the Author

Mark Lamendola

Mark is an expert in maintenance management, having racked up an impressive track record during his time working in the field. He also has extensive knowledge of, and practical expertise with, the National Electrical Code (NEC). Through his consulting business, he provides articles and training materials on electrical topics, specializing in making difficult subjects easy to understand and focusing on the practical aspects of electrical work.

Prior to starting his own business, Mark served as the Technical Editor on EC&M for six years, worked three years in nuclear maintenance, six years as a contract project engineer/project manager, three years as a systems engineer, and three years in plant maintenance management.

Mark earned an AAS degree from Rock Valley College, a BSEET from Columbia Pacific University, and an MBA from Lake Erie College. He’s also completed several related certifications over the years and even was formerly licensed as a Master Electrician. He is a Senior Member of the IEEE and past Chairman of the Kansas City Chapters of both the IEEE and the IEEE Computer Society. Mark also served as the program director for, a board member of, and webmaster of, the Midwest Chapter of the 7x24 Exchange. He has also held memberships with the following organizations: NETA, NFPA, International Association of Webmasters, and Institute of Certified Professional Managers.

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