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

70-754 NATIONAL ELECTRICAL CODE 725-3. Classifications. A remote-control, signaling, or power-limited circuit is the portion of the wiring system between the load side of the overcurrent device or the power-limited supply and all connected equipment, and shall be Class 1, Class 2, or Class 3 as defined in (a) and (b) below. (a) Class 1 Circuits. Circuits that comply with Part B of this article and in which the voltage and power limitations are in accordance with Section 725-11. (b) Class 2 and Class 3 Circuits. Circuits that comply with Part C of this article and in which the voltage and power limitations are in accordance with Section 725-31. (FPN): Due to their power limitations, both Class 2 and 3 circuits consider safety from a fire initiation standpoint. In addition, Class 2 circuits provide acceptable protection from electric shock. However, since Class 3 circuits permit higher allowable levels of voltage and current, additional safeguards are specified to provide protection against the electric shock hazard that could be encountered. 725-4. Safety-Control Equipment. Remote-control circuits to safetycontrol equipment shall be classified as Class 1 if the failure of the equipment to operate introduces a direct fire or life hazard. Room thermostats, water temperature regulating devices, and similar controls used in conjunction with electrically controlled household heating and air conditioning shall not be considered safety-control equipment. 725-5. Communications Cables. Class 1 circuits shall not be run in the same cable with communications circuits. Class 2 and Class 3 circuit conductors shall be permitted in the same cable with communications circuits, in which case the Class 2 and Class 3 circuits shall be classified as communications circuits and shall meet the requirements of Article 800. The cables shall be listed as communications cables or multipurpose cables. Exception: Cables constructed of individually listed Class 2, Class 3, and communications cables under a common jacket shall not be required to be classified as communications cables. The fire resistance rating of the composite cable shall be determined by the performance of the composite cable. 725-6. Access to Electrical Equipment Behind Panels Designed to Allow Access. Access to equipment shall not be denied by an accumulation of wires and cables that prevents removal of panels, including suspended ceiling panels. B. Class 1 Circuits 725-11. Power Limitations for Class 1 Circuits. (a) Class 1 Power-Limited Circuits. These circuits shall be supplied from a source having a rated output of not more than 30 volts and 1000 voltamperes. Power sources other than transformers shall be protected by overcurrent devices rated at not more than 167 percent of the volt-ampere rating of the source divided by the rated voltage. The overcurrent devices shall not be interchangeable with overcurrent devices of higher ratings. The overcurrent device shall be permitted to be an integral part of the power supply. (1) Transformers. Transformers used to supply power-limited Class 1 circuits shall comply with Article 450.