X-RAY EQUIPMENT

70-675 conductor, or shall be permitted as a separate conductor and shall be permitted to be in contact with the cable. (d) 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 flame-retardant or the cable or each cable subassembly shall be covered with a closely wound fireproof tape. 650-6. 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. Cables shall not be placed in contact with other conductors. 650-7. Overcurrent Protection. Circuits shall be so arranged that all conductors shall be protected from overcurrent by an overcurrent device rated at not more than 6 amperes. Exception: The main supply conductors and the common-return conductors. ARTICLE 660 - X-RAY EQUIPMENT A. General 660-1. Scope. This article covers all X-ray equipment operating at any frequency or voltage for industrial or other nonmedical or nondental use. (FPN): See Article 517, Part E, for X-ray installations in health care facilities. I Nothing in this article shall be construed as specifying safeguards against the useful beam or stray X-ray radiation. (FPN 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. (FPN 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 are obtainable from NCRP Publications, 7910 Woodmont Ave., Suite 1016, Bethesda, MD 20814. 660-2. 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 to be installed in a vehicle or that may be readily disassembled for transport in a vehicle. 70-676 NATIONAL ELECTRICAL CODE 660-3. Hazardous (Classified) Locations. Unless approved for the location, X-ray and related equipment shall not be installed or operated in hazardous (classified) locations. (FPN): See Article 517, Part D. 660-4. Connection to Supply Circuit. (a) Fixed and Stationary Equipment. Fixed and stationary X-ray equipment shall be connected to the power supply by means of a wiring method meeting the general requirements of this Code. Exception: 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. (b) Portable, Mobile, and Transportable Equipment. Individual 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 equipment 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. (c) Over 600 Volts, Nominal. Circuits and equipment operated at more than 600 volts, nominal, shall comply with Article 710. 660-5. 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 disconnecting means shall be operable from a location readily accessible from the X-ray control. For equipment connected to a 120-volt, nominal, branch circuit of 30 amperes or less, a grounding-type attachment plug cap and receptacle of proper rating shall be permitted to serve as a disconnecting means. 660-6. Rating of Supply Conductors and Overcurrent Protection. (a) Branch-Circuit Conductors. The ampacity of supply branch-circuit conductors and the overcurrent protective devices shall not be less than 50 percent of the momentary rating or 100 percent of the long-time rating, whichever is the greater. (b) 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 (a)] of the two largest X-ray apparatus plus 20 percent of the momentary ratings of other X-ray apparatus. (FPN): 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 conductor sizes, rating of disconnect means, and overcurrent protection. ARTICLE 660 - X-RAY EQUIPMENT 70-677 660-7. Wiring Terminals. X-ray equipment 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. Exception: Where provided with a permanently attached cord or a cord set. 660-8. Number of Conductors in Raceway. The number of control circuit conductors installed in a raceway shall be determined in accordance with