Article 660

1. X-Ray EquipmentSupply. The installation of the dc power supply shall comply with either of the following:
2. Conductors. Conductors shall comply with 650.6(A) through (D).
   1. Size. The minimum conductor size shall be not less than 28 AWG for electronic signal circuits and not less than 26 AWG for electromagnetic valve supply and the like. The minimum conductor size of a main common-return conductor in the electromagnetic supply shall not be less than 14 AWG.
   2. Insulation. Conductors shall have thermoplastic or ther‐ mosetting insulation.
   3. Conductors to Be Cabled. Except for the common-return conductor and conductors inside the organ proper, the organ sections and the organ console conductors shall be cabled. The common-return conductors shall be permitted under an addi‐ tional covering enclosing both cable and return conductor, or they shall be permitted as a separate conductor and shall be permitted to be in contact with the cable.
   4. Cable Covering. Each cable shall be provided with an outer covering, either overall or on each of any subassemblies of grouped conductors. Tape shall be permitted in place of a covering. Where not installed in metal raceway, the covering shall be resistant to flame spread, or the cable or each cable subassembly shall be covered with a closely wound listed fire‐ proof tape.
   Informational Note: One method of determining that cable is resistant to flame spread is by testing the cable to the VW-1 (vertical-wire) flame test in ANSI/UL 1581-2011, Reference Stand‐ ard for Electrical Wires, Cables and Flexible Cords.
3. Installation of Conductors. Cables shall be securely fastened in place and shall be permitted to be attached directly to the organ structure without insulating supports. Splices shall not be required to be enclosed in boxes or other enclosures. Control equipment and busbars connecting common-return conductors shall be permitted to be attached directly to the organ structure without insulation supports. Abandoned cables that are not terminated at equipment shall be identified with a tag of sufficient durability to withstand the environment involved.
4. Overcurrent Protection. Circuits shall be so arranged that 20 AWG through 28 AWG conductors shall be protected by an overcurrent device rated at not more than 6 amperes. Other conductor sizes shall be protected in accordance with their

Part I. General

1. Scope. This article covers all X-ray equipment operat‐ ing at any frequency or voltage for industrial or other nonmed‐ ical or nondental use.Informational Note: See Article 517, Part V, for X-ray installa‐ tions in health care facilities.Nothing in this article shall be construed as specifying safe‐ guards against the useful beam or stray X-ray radiation.Informational Note No. 1: Radiation safety and performance requirements of several classes of X-ray equipment are regulated under Public Law 90-602 and are enforced by the Department of Health and Human Services.Informational Note No. 2: In addition, information on radiation protection by the National Council on Radiation Protection and Measurements is published as Reports of the National Council on Radiation Protection and Measurement. These reports can be obtained from NCRP Publications, 7910 Woodmont Ave., Suite 1016, Bethesda, MD 20814.
2. Definitions.Long-Time Rating. A rating based on an operating interval of 5 minutes or longer.Mobile. X-ray equipment mounted on a permanent base with wheels and/or casters for moving while completely assembled.Momentary Rating. A rating based on an operating interval that does not exceed 5 seconds.Portable. X-ray equipment designed to be hand-carried.Transportable. X-ray equipment that is to be installed in a vehicle or that may be readily disassembled for transport in a vehicle.
3. Hazardous (Classified) Locations. Unless identified for the location, X-ray and related equipment shall not be installed or operated in hazardous (classified) locations.Informational Note: See Article 517, Part IV.
4. Connection to Supply Circuit.
   1. Fixed and Stationary Equipment. Fixed and stationary X- ray equipment shall be connected to the power supply byARTICLE 660 — X-RAY EQUIPMENT 660.47
      means of a wiring method meeting the general requirements of this Code. Equipment properly supplied by a branch circuit rated at not over 30 amperes shall be permitted to be supplied through a suitable attachment plug cap and hard-service cable or cord.
   2. Portable, Mobile, and Transportable Equipment. Individ‐ ual branch circuits shall not be required for portable, mobile, and transportable X-ray equipment requiring a capacity of not over 60 amperes. Portable and mobile types of X-ray equip‐ ment of any capacity shall be supplied through a suitable hard- service cable or cord. Transportable X-ray equipment of any capacity shall be permitted to be connected to its power supply by suitable connections and hard-service cable or cord.
   3. Over 1000 Volts, Nominal. Circuits and equipment oper‐ ated at more than 1000 volts, nominal, shall comply with Arti‐ cle 490.
5. Disconnecting Means. A disconnecting means of adequate capacity for at least 50 percent of the input required for the momentary rating, or 100 percent of the input required for the long-time rating, of the X-ray equipment, whichever is greater, shall be provided in the supply circuit. The disconnect‐ ing means shall be located within sight from the X-ray control and readily accessible.
   Exception: The disconnecting means for the X-ray equipment shall notbe required under either of the following conditions, provided that the controller disconnecting means is lockable in accordance with 110.25:
   1. Where such a location of the disconnecting means for the X-ray equipment is impracticable or introduces additional or increased hazards to persons or property
   2. In industrial installations, with written safety procedures, where conditions of maintenance and supervision ensure that only qualified persons service the equipment
6. Rating of Supply Conductors and Overcurrent Protec‐ tion.
   1. Branch-Circuit Conductors. The ampacity of supply branch-circuit conductors and the overcurrent protective devi‐ ces shall not be less than 50 percent of the momentary rating or 100 percent of the long-time rating, whichever is greater.
   2. Feeder Conductors. The rated ampacity of conductors and overcurrent devices of a feeder for two or more branch circuits supplying X-ray units shall not be less than 100 percent of the momentary demand rating [as determined by 660.6(A)] of the two largest X-ray apparatus plus 20 percent of the momentary ratings of other X-ray apparatus.
   Informational Note: The minimum conductor size for branch and feeder circuits is also governed by voltage regulation requirements. For a specific installation, the manufacturer usually specifies minimum distribution transformer and conduc‐ tor sizes, rating of disconnect means, and overcurrent protec‐ tion.
7. Wiring Terminals. X-ray equipment not provided with a permanently attached cord or cord set shall be provided with suitable wiring terminals or leads for the connection of power- supply conductors of the size required by the rating of the branch circuit for the equipment.

1. Minimum Size of Conductors. Size 18 AWG or 16 AWG fixture wires, as specified in 725.49, and flexible cords 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.
2. 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.

Part II. Control

1. Fixed and Stationary Equipment.
   1. Separate Control Device. A separate control device, in addition to the disconnecting means, shall be incorporated in the X-ray control supply or in the primary circuit to the high- voltage transformer. This device shall be a part of the X-ray equipment but shall be permitted in a separate enclosure immediately adjacent to the X-ray control unit.
   2. Protective Device. A protective device, which shall be permitted to be incorporated into the separate control device, shall be provided to control the load resulting from failures in the high-voltage circuit.
2. Portable and Mobile Equipment. Portable and mobile equipment shall comply with 660.20, but the manually control‐ led device shall be located in or on the equipment.

1. Industrial and Commercial Laboratory Equipment.
   1. Radiographic and Fluoroscopic Types. All radiographic- and fluoroscopic-type equipment shall be effectively enclosed or shall have interlocks that de-energize the equipment auto‐ matically to prevent ready access to live current-carrying parts.
   2. Diffraction and Irradiation Types. Diffraction- and irradiation-type equipment or installations not effectively enclosed or not provided with interlocks to prevent access to uninsulated live parts during operation shall be provided with a positive means to indicate when they are energized. The indica‐ tor shall be a pilot light, readable meter deflection, or equiva‐ lent means.
2. Independent Control. Where more than one piece of equipment is operated from the same high-voltage circuit, each piece or each group of equipment as a unit shall be provided with a high-voltage switch or equivalent disconnecting means. This disconnecting means shall be constructed, enclosed, or located so as to avoid contact by persons with its live parts.

Part III. Transformers and Capacitors

1. General. Transformers and capacitors that are part of an X-ray equipment shall not be required to comply with Arti‐ cles 450 and 460.
2. Capacitors. Capacitors shall be mounted within enclo‐ sures of insulating material or grounded metal.

Part IV. Guarding and Grounding

660.47 General.

1. 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
   1. ARTICLE 665 — INDUCTION AND DIELECTRIC HEATING EQUIPMENT
      from the high-voltage equipment to X-ray tubes and other high-voltage components shall be made with high-voltage shiel‐ ded cables.
2. Low-Voltage Cables. Low-voltage cables connecting to oil- filled units that are not completely sealed, such as transform‐ ers, condensers, oil coolers, and high-voltage switches, shall have insulation of the oil-resistant type.
3. Grounding. 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, and so forth) shall be grounded in the manner specified in Article 250. Portable and mobile equipment shall be provided with an approved grounding-type attachment plug cap.

Exception: Battery-operated equipment.