For your convenience we have included the following excerpts from NEC® (National Electrical Code®).

Article 517-3 defines Patient Care Area as any portion of a health care facility wherein patients are intended to be examined or treated. Areas of a health care facility in which patient care is administered are classified as general care areas or critical care areas, either of which may be classified as a wet location. General Care Areas are patient bedrooms, examining rooms, treatment, rooms, clinics and similar areas in which it is intended that the patient shall come in contact with ordinary appliances such as nurse call system, electrical beds, examining lamps, telephone and entertainment devices. In such areas, it may also be intended that patients be connected to electro-medical devices (such as heating pads, electrocardiographs, drainage pumps, monitors, otoscopes, ophthalmoscopes, intravenous lines, etc.). Critical Care Areas are those special care units, intensive care units, coronary care units, angiography laboratories, cardiac catheterization laboratories, delivery rooms, operating rooms, and similar areas in which patients are intended to be subjected to invasive procedures and connected to line-operated, electro-medical devices. Patient Vicinity is an area in which patients are normally cared for, the patient vicinity is the space with surfaces likely to be contacted by the patient or an attendant who can touch the patient. Typically, in a patient room, this encloses a space within the room no less than 6 feet (1.83 m) beyond the perimeter of the bed in its nominal location, and extending vertically no less than 7 1/2 feet (2.29 m) above the floor.

Article 517-11 General Installation/Construction Criteria
In this article it is stated that Control of Electrical Shock Hazard requires limitation of electrical current that might flow in the electric circuit involving the patient's body. It is difficult to prevent the occurrence of a conductive or capacitive path from the patient's body to some grounded object, because the path may be established accidentally or through instrumentation directly connected to the patient.

Article 517-64 Low Voltage Equipment and Instruments
(a) Equipment Requirements, Low Voltage Equipment that is frequently in contact with the bodies of persons or has exposed current-carrying elements shall:
· Operate on an electrical potential of 10 Volts or less, or
· Be approved as intrinsically safe or double insulated equipment.
· Be moisture-resistant.
(b) Power Supplies. Power shall be supplied to low-voltage equipment from:
· Individual portable isolation transformer (autotransformer shall not be used) connected to an isolated power circuit receptacle by means of an appropriate cord and attachment plug, or
· Common low-voltage isolating transformer installed in an other-than-hazardous (classified) location or
· Individual dry cell batteries, or
· Common batteries made up of storage cells located in an other-than-hazardous (classified) location.

Material contained herein is reproduced and/or summarized from the 1999 National Electrical Code® Copyright© 1998, National Fire Protection Association. This material is not the complete and official position of the NFPA, which is represented solely by the standard and its entirety.

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