It has been a while since I wrote an article on healthcare systems. Almost my entire family is involved in that industry, and most of the conversation around the holiday dinner table last year was focused on hospitals and related healthcare. Without our medical professionals and their years of training and experience, healthcare in our country would not be what it is today. 

I don’t say much about my previous involvement in listing hospital equipment and the years of training I have provided on Article 517 covering healthcare facilities in the National Electrical Code. However, without the requirements in Article 517 on healthcare and other similar safety-related requirements in the NEC, our nation’s healthcare would suffer. Many electrical design engineers, electrical contractors, electricians and maintenance personnel specialize in healthcare and make these installations safe.

One of the most important installation requirements in a hospital or any similar healthcare facility is Part III of Article 517, which covers the essential electrical system (EES). 

NFPA 110, Standard for Emergency and Standby Power Systems, provides a complete and functioning emergency power source system, coupled to a system of conductors; disconnecting means; overcurrent protective devices; transfer switches; and control, supervisory and support devices up to and including the load terminals of the transfer equipment. This equipment is needed for the system to operate as a safe and reliable source of electric power. 

System and space requirements

NFPA 110 requirements are the basis for emergency systems in hospitals. There are two levels of classification for emergency systems recognized in NFPA 110: critical (Level 1) or less critical to life and safety (Level 2). Level 1 (Type 1) systems and Level 2 (Type 2) systems for EES for healthcare facilities are composed of separate branches capable of supplying a limited amount of lighting and power service. These systems are considered essential for life and safety and orderly cessation of procedures during the time normal electrical service is interrupted for any reason.

In Part III of Article 517, the EES is made up of three separate electrical branches: life safety, critical and equipment. The use of the term “branch” does not infer a “branch circuit” as one might first think. It deals with separate parts of the power system. 

In addition, there are four different patient-care space categories helpful in determining the use and application of the three branches. A “Category 1 Space” is one in which failure of equipment or a system is likely to cause major injury or death of patients, staff members or visitors, such as in an operating room or a critical-care patient bedroom. 

A “Category 2 Space” is one in which failure of equipment or system is likely to cause minor injury to patients, staff members or visitors, such as in a general-care patient bedroom. 

A “Category 3 Space” is one in which the failure of equipment or system is not likely to cause injury to patients, staff members or visitors, such as exam or treatment rooms and dental care facilities, but not oral surgical areas. 

A “Category 4 Space” is one in which the failure of equipment or system is not likely to have a physical effect on patient care, such as nursing stations, waiting rooms, laboratories and other such support locations.

The life safety branch of the EES must meet the requirements of Article 700, Emergency Systems, with some exceptions. Similar to the requirements in Article 700, the life safety branch for hospitals covers power to means of egress illumination and exit and exit directional signs. It also covers alarm and alerting systems, such as fire alarm systems and alarms for nonflammable medical gases installed on the life safety branch to ensure warning of low levels of these important gases. 

Hospital HVAC systems control is permitted on the life safety branch, since heating, ventilation and air conditioning controls can affect smoke control and smoke evacuation systems. Communications systems for issuing instructions during emergencies are also permitted on the life safety branch. 

Generator accessories, such as battery chargers, task illumination for the area and power to receptacles in those locations, are important in maintaining power operation during outages. Elevators for emergency use to access operating rooms and automatic doors for building egress are also permitted. 

Next month’s article will wrap up the discussion of EESs.

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