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

(b) Common Bonding Grid. These parts shall be connected to a common bonding grid with a solid, copper conductor, insulated, covered, or bare, not smaller than No. 8. Connection shall be made by pressure connectors or clamps of stainless steel, brass, copper, or copper alloy. The common bonding grid shall be permitted to be any of the following: (1) The structural reinforcing steel of a concrete pool where the reinforcing rods are bonded together by the usual steel tie wires or the equivalent; or (2) The wall of a bolted or welded metal pool; or (3) A solid, copper conductor, insulated, covered, or bare, not smaller than No. 8. (c) Pool Water Heaters. For pool water heaters rated at more than 50 amperes that have specific instructions regarding bonding and grounding, only those parts designated to be bonded shall be bonded, and only those parts designated to be grounded shall be grounded. 680-23. Underwater Audio Equipment. All underwater audio equipment shall be identified for the purpose. (a) Speakers. Each speaker shall be mounted in an approved metal forming shell, the front of which is enclosed by a captive metal screen, or equivalent, that is bonded to and secured to the forming shell by a positive locking device that assures a low-resistance contact and requires a tool to open for installation or servicing of the speaker. The forming shell shall be installed in a recess in the wall or floor of the pool. (b) Wiring Methods. Rigid metal conduit or intermediate metal conduit of brass or other identified corrosion-resistant metal or rigid nonmetallic conduit shall extend from the forming shell to a suitable junction box or other enclosure as provided in Section 680-21. Where rigid nonmetallic 70-704 NATIONAL ELECTRICAL CODE conduit is used, a No. 8 insulated copper conductor shall be installed in this conduit with provisions for terminating in the forming shell and the junction box. The termination of the No. 8 conductor in the forming shell shall be covered with, or encapsulated in, a suitable potting compound to protect such connection from the possible deteriorating effect of pool water. (c) Forming Shell and Metal Screen. The forming shell and metal screen shall be of brass or other approved corrosion-resistant metal. 680-24. Grounding. The following equipment shall be grounded: (1) wetniche and no-niche underwater lighting fixtures; (2) dry-niche underwater lighting fixtures; (3) all electric equipment located within 5 feet (1.52 m) of the inside wall of the pool; (4) all electric equipment associated with the recirculating system of the pool; (5) junction boxes; (6) transformer enclosures; (7) ground-fault circuit-interrupters; (8) panelboards that are not part of the service equipment and that supply any electric equipment associated with the pool. 680-25. Methods of Grounding. (a) General. The following provisions shall apply to the grounding of underwater lighting fixtures, junction boxes, metal transformer enclosures, panelboards, motors, and other electrical enclosures and equipment. (b) Pool Lighting Fixtures and Related Equipment. (1) Wet-niche, dry-niche, or no-niche lighting fixtures shall be connected to an equipment grounding conductor sized in accordance with Table 250-95 but not smaller than No. 12. It shall be an insulated copper conductor and shall be installed with the circuit conductors in rigid metal conduit, intermediate metal conduit, or rigid nonmetallic conduit. Exception No. 1: Electrical metallic tubing shall be permitted to be used to protect conductors where installed on or within buildings. Exception No. 2: The equipment grounding conductor between the wiring chamber of the secondary winding of a transformer and a junction box shall be sized in accordance with the overcurrent device in this circuit. (2) The junction box, transformer enclosure, or other enclosure in the supply circuit to a wet-niche or no-niche lighting fixture and the fieldwiring chamber of a dry-niche lighting fixture shall be grounded to the equipment grounding terminal of the panelboard. This terminal shall be directly connected to the panelboard enclosure. The equipment grounding conductor shall be installed without joint or splice. Exception No. 1: Where more than one underwater lighting fixture is supplied by the same branch circuit, the equipment grounding conductor, installed between the junction boxes, transformer enclosures, or other enclosures in the supply circuit to wet-niche fixtures, or between the fieldwiring compartments of dry-niche fixtures, shall be permitted to be terminated on grounding terminals. Exception No. 2: Where the underwater lighting fixture is supplied from a transformer, ground-fault circuit-interrupter, clock-operated switch, or a manual snap switch that is located between the panelboard and a junction box connected to the conduit that extends directly to the underwater lighting ARTICLE 680 - SWIMMING POOLS, FOUNTAINS 70-705 fixture, the equipment grounding conductor shall be permitted to terminate on grounding terminals on the transformer, ground-fault circuitinterrupter, clock-operated switch enclosure, or an outlet box used to enclose a snap switch. (3) Wet-niche or no-niche lighting fixtures that are supplied by a flexible cord or cable shall have all exposed noncurrent-carrying metal parts grounded by an insulated copper equipment grounding conductor that is an integral part of the cord or cable. This grounding conductor shall be connected to a grounding terminal in the supply junction box, transformer enclosure, or other enclosure. The grounding conductor shall not be smaller than the supply conductors and not smaller than No. 16. (c) Motors. Pool-associated motors shall be connected to an equipment grounding conductor sized in accordance with Table 250-95 but not smaller than No. 12. It shall be an insulated copper conductor and shall be installed with the circuit conductors in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, or Type MC cable listed for the application. Exception No. 1: Electrical metallic tubing shall be permitted to be used to protect conductors where installed on or within buildings. Exception No. 2: Where necessary to employ flexible connections at or adjacent to the motor, liquidtight flexible metal or nonmetallic conduit with approved fittings shall be permitted. Exception No. 3: Any of the wiring methods recognized in Chapter 3 of this Code that contain an insulated or covered equipment grounding conductor not smaller than No. 12 shall be permitted to be used in the interior of a one-family dwelling. Exception No. 4: Flexible cord shall be permitted in accordance with