not apply in other-than-hazardous (classified) locations.
(D) Remote-Control Stations. Wall-mounted remote- control stations for remote-control switches operating at 24 volts or less shall be permitted to be installed in any anesthetizing location.
(E) Location of Isolated Power Systems. Where an isolated power system is utilized, the isolated power equipment shall be listed as isolated power equipment. Isolated power equipment and its grounded primary feeder shall be permitted to be located in an anesthetizing location, provided it is installed above a hazardous (classified) location or in an other-than-hazardous (classified) location.
(F) Circuits in Anesthetizing Locations. Except as per- mitted above, each power circuit within, or partially within, a flammable anesthetizing location as referred to in 517.60 shall be isolated from any distribution system supplying other-than- anesthetizing locations.
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 comply with one of the following:
(1) Operate on an electrical potential of 10 volts or less
(2) Be approved as intrinsically safe or double- insulated equipment
(3) Be moisture resistant
(B) Power Supplies. Power shall be supplied to low- voltage equipment from one of the following:
(1) An individual portable isolating transformer (autotrans-formers shall not be used) connected to an isolated power circuit receptacle by means of an appropriate cord and attachment plug
(2) A common low-voltage isolating transformer installed in an other-than-hazardous (classified) location
(3) Individual dry-cell batteries
(4) Common batteries made up of storage cells located in an other-than-hazardous (classified) location
(C) Isolated Circuits. Isolating-type transformers for sup plying low-voltage circuits shall have both of the following:
(1) Approved means for insulating the secondary circuit from the primary circuit
(2) The core and case connected to an equipment grounding conductor
(D) Controls. Resistance or impedance devices shall be permitted to control low-voltage equipment but shall not be used to limit the maximum available voltage to the equipment.
(E) Battery-Powered Appliances. Battery-powered appliances shall not be capable of being charged while in operation unless their charging circuitry incorporates an integral isolating-type transformer.
(F) Receptacles or Attachment Plugs. Any receptacle or attachment plug used on low-voltage circuits shall be of a type that does not permit interchangeable connection with circuits of higher voltage.
FPN: Any interruption of the circuit, even circuits as low as 10 volts, either by any switch or loose or defective connections anywhere in the circuit, may produce a spark that is sufficient to ignite flammable anesthetic agents.
V. X-Ray Installations
Nothing in this part 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, P.O. Box 30175, Washington, DC 20014.
517.71 Connection