Resolución 2535: adopta el Código Eléctrico Nacional, versión 1993. (Sustituye el Anejo A del Reglamento 4435)

(b) Exposed and in a Dry Location. The extension is run exposed and in a dry location. (c) Nonmetallic Surface Extensions. For nonmetallic surface extensions, the building is occupied for residential or office purposes and does not exceed the height limitations specified in Section 336-4(a). 70-238 NATIONAL ELECTRICAL CODE (c1) (Alternate to (c)). For aerial cable, the building is occupied for industrial purposes, and the nature of the occupancy requires a highly flexible means for connecting equipment. (FPN): See Section 310-10 for temperature limitation of conductors. 342-4. Uses Not Permitted. Nonmetallic extensions shall not be used: (a) Aerial Cable. As aerial cable to substitute for one of the general wiring methods specified by this Code. (b) Unfinished Areas. In unfinished basements, attics, or roof spaces. (c) Voltage Between Conductors. Where the voltage between conductors exceeds 150 volts for nonmetallic surface extension and 300 volts for aerial cable. (d) Corrosive Vapors. Where subject to corrosive vapors. (e) Through a Floor or Partition. Where run through a floor or partition, or outside the room in which it originates. 342-5. Splices and Taps. Extensions shall consist of a continuous unbroken length of the assembly, without splices, and without exposed conductors between fittings. Taps shall be permitted where approved fittings completely covering the tap connections are used. Aerial cable and its tap connectors shall be provided with an approved means for polarization. Receptacle-type tap connectors shall be of the locking-type. 342-6. Fittings. Each run shall terminate in a fitting that covers the end of the assembly. All fittings and devices shall be of a type identified for the use. 342-7. Installation. Nonmetallic extensions shall be installed as specified in (a) and (b) below. (a) Nonmetallic Surface Extensions. (1) One or more extensions shall be permitted to be run in any direction from an existing outlet, but not on the floor or within 2 inches (50.8 mm) from the floor. (2) Nonmetallic surface extensions shall be secured in place by approved means at intervals not exceeding 8 inches (203 mm). Exception: Where connection to the supplying outlet is made by means of an attachment plug, the first fastening shall be permitted 12 inches (305 mm) or less from the plug. There shall be at least one fastening between each two adjacent outlets supplied. An extension shall be attached only to woodwork or plaster finish, and shall not be in contact with any metal work or other conductive material other than with metal plates on receptacles. (3) A bend that reduces the normal spacing between the conductors shall be covered with a cap to protect the assembly from physical damage. (b) Aerial Cable. (1) Aerial cable shall be supported by its messenger cable and securely attached at each end with approved clamps and turnbuckles. Intermediate supports shall be provided at not more than 20-foot (6.1-m) intervals. Cable