shall be permitted for the control and operating
circuits of X-ray and auxiliary equipment where
protected by not larger than 20-ampere overcurrent
devices.
517.75 Equipment Installations. All equipment for new X-ray installations and all used or reconditioned X-ray equipment moved to and reinstalled at a new location shall be of an approved type.
517.76 Transformers and Capacitors. Transformers and capacitors that are part of X-ray equipment shall not be required to comply with Articles 450 and 460.
Capacitors shall be mounted within enclosures of insulating material or grounded metal.
517.77 Installation of High-Tension X-Ray Cables.
Cables with grounded shields connecting X-ray tubes and image intensifiers shall be permitted to be installed in cable trays or cable troughs along with X- ray equipment control and power supply conductors without the need for barriers to separate the wiring.
517.78 Guarding and Grounding.
(A) High-Voltage Parts. All high-voltage parts, including X-ray tubes, shall be mounted within grounded enclosures. Air, oil, gas, or other suitable insulating media shall be used to insulate the high- voltage from the grounded enclosure. The connection from the high-voltage equipment to X-ray tubes and other high-voltage components shall be made with high-voltage shielded cables.
(B) Low-Voltage Cables. Low-voltage cables connecting to oil-filled units that are not completely sealed, such as transformers, condensers, oil coolers, and high-voltage switches, shall have insulation of the oil-resistant type.
(C) Non-Current-Carrying Metal Parts. Non-current- carrying metal parts of X-ray and associated equipment (controls, tables, X-ray tube supports, transformer tanks, shielded cables, X-ray tube heads, etc.) shall be connected to an equipment grounding conductor in the manner specified in Article 250, as modified by 517.13(A) and (B).
VI. Communications, Signaling Systems, Data
Systems, Fire Alarm Systems, and Systems Less
Than 120 Volts, Nominal
517.80 Patient Care Areas. Equivalent insulation and isolation to that required for the electrical distribution systems in patient care areas shall be
provided for communications, signaling systems, data system circuits, fire alarm systems, and systems less than 120 volts, nominal.
Secondary circuits of transformer-powered communications or signaling systems shall not be required to be enclosed in raceways unless otherwise specified by Chapter 7 or 8. [99:4.4.2.2.4.6]
FPN: An acceptable alternate means of providing isolation for patient/nurse call systems is by the use of nonelectrified signaling, communications, or control devices held by the patient or within reach of the patient.
517.81 Other-Than-Patient-Care Areas. In other- than-patient-care areas, installations shall be in accordance with the appropriate provisions of Articles 640, 725, 760, and 800.
517.82 Signal Transmission Between Appliances.
(A) General. Permanently installed signal cabling from an appliance in a patient location to remote appliances shall employ a signal transmission system that prevents hazardous grounding interconnection of the appliances.
FPN: See 517.13(A) for additional grounding requirements in patient care areas.
(B) Common Signal Grounding Wire. Common signal grounding wires (i.e., the chassis ground for single- ended transmission) shall be permitted to be used between appliances all located within the patient care vicinity, provided the appliances are served from the same reference grounding point.
VII. Isolated Power Systems
517.160 Isolated Power Systems. (A) Installations.
(1) Isolated Power