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

(d) Every Switch. Every disconnecting means in the refrigerant motorcompressor circuit between the point of attachment to the feeder and the point of connection to the refrigerant motor-compressor shall comply with the requirements of Section 440-12. (e) Disconnecting Means Rated in Excess of 100 Horsepower. Where the rated-load or locked-rotor current as determined above would indicate a disconnecting means rated in excess of 100 horsepower, the provisions of Section 430-109, Exception No. 4 shall apply. 70-436 NATIONAL ELECTRICAL CODE 440-13. Cord-Connected Equipment. For cord-connected equipment such as room air conditioners, household refrigerators and freezers, drinking water coolers, and beverage dispensers, a separable connector or an attachment plug and receptacle shall be permitted to serve as the disconnecting means. See also Section 440-63. 440-14. Location. Disconnecting means shall be located within sight from and readily accessible from the air-conditioning or refrigerating equipment. The disconnecting means shall be permitted to be installed on or within the air-conditioning or refrigerating equipment. Exception: Cord- and plug-connected appliances. (FPN): See Parts G and I of Article 430 for additional requirements. C. Branch-Circuit Short-Circuit and Ground-Fault Protection 440-21. General. The provisions of Part C specify devices intended to protect the branch-circuit conductors, control apparatus, and motors in circuits supplying hermetic refrigerant motor-compressors against overcurrent due to short circuits and grounds. They are in addition to or amendatory of the provisions of Article 240. 440-22. Application and Selection. (a) Rating or Setting for Individual Motor-Compressor. The motorcompressor branch-circuit short-circuit and ground-fault protective device shall be capable of carrying the starting current of the motor. A protective device having a rating or setting not exceeding 175 percent of the motorcompressor rated-load current or branch-circuit selection current, whichever is greater, shall be permitted, provided that, where the protection specified is not sufficient for the starting current of the motor, the rating or setting shall be permitted to be increased, but shall not exceed 225 percent of the motor rated-load current or branch-circuit selection current, whichever is greater. Exception: The rating of the branch-circuit short-circuit and groundfault protective device shall not be required to be less than 15 amperes. (b) Rating or Setting for Equipment. The equipment branch-circuit short-circuit and ground-fault protective device shall be capable of carrying the starting current of the equipment. Where the hermetic refrigerant motor-compressor is the only load on the circuit, the protection shall conform with Section 440-22(a). Where the equipment incorporates more than one hermetic refrigerant motor-compressor or a hermetic refrigerant motor-compressor and other motors or other loads, the equipment shortcircuit and ground-fault protection shall conform with Section 430-53 and the following: (1) Where a hermetic refrigerant motor-compressor is the largest load connected to the circuit, the rating or setting of the branch-circuit shortcircuit and ground-fault protective device shall not exceed the value specified in Section 440-22(a) for the largest motor-compressor plus the sum of ARTICLE 440 - AIR CONDITIONING EQUIPMENT 70-437 the rated-load current or branch-circuit selection current, whichever is greater, of the other motor-compressor(s) and the ratings of the other loads supplied. (2) Where a hermetic refrigerant motor-compressor is not the largest load connected to the circuit, the rating or setting of the branch-circuit short-circuit and ground-fault protective device shall not exceed a value equal to the sum of the rated-load current or branch-circuit selection current, whichever is greater, rating(s) for the motor-compressor(s) plus the value specified in Section 430-53(c)(4) where other motor loads are supplied, or the value specified in Section 240-3 where only nonmotor loads are supplied in addition to the motor-compressor(s). Exception No. 1: Equipment that will start and operate on a 15- or 20-ampere 120-volt, or 15-ampere 208- or 240-volt single-phase branch circuit, shall be permitted to be protected by the 15- or 20-ampere overcurrent device protecting the branch circuit, but if the maximum branchcircuit short-circuit and ground-fault protective device rating marked on the equipment is less than these values, the circuit protective device shall not exceed the value marked on the equipment nameplate. Exception No. 2: The nameplate marking of cord- and plug-connected equipment rated not greater than 250 volts, single-phase, such as household refrigerators and freezers, drinking water coolers, and beverage dispensers, shall be used in determining the branch-circuit requirements, and each unit shall be considered as a single motor unless the nameplate is marked otherwise. (c) Protective Device Rating Not to Exceed the Manufacturer's Values. Where maximum protective device ratings shown on a manufacturer's heater table for use with a motor controller are less than the rating or setting selected in accordance with Sections 440-22(a) and (b), the protective device rating shall not exceed the manufacturer's values marked on the equipment. D. Branch-Circuit Conductors 440-31. General. The provisions of Part D and Articles 300 and 310 specify sizes of conductors required to carry the motor current without overheating under the conditions specified, except as modified in Section 440-6(a), Exception No. 1. The provisions of these articles shall not apply to integral conductors of motors, motor controllers and the like, or to conductors that form an integral part of approved equipment. (FPN): See Sections 300-1(b) and 310-1 for similar requirements. 440-32. Single Motor-Compressor. Branch-circuit conductors supplying a single motor-compressor shall have an ampacity not less than 125 percent of either the motor-compressor rated-load current or the branch-circuit selection current, whichever is greater. 440-33. Motor-Compressor(s) With or Without Additional Motor Loads. Conductors supplying one or more motor-compressor(s) with or without additional load(s) shall have an ampacity not less than the sum of the rated-load or branch-circuit selection current ratings, whichever is larger, 70-438 NATIONAL ELECTRICAL CODE of all the motor-compressor(s) plus the full-load currents of the other motor(s), plus 25 percent of the highest motor or motor-compressor rating in the group. Exception No. 1: Where the circuitry is so interlocked as to prevent the starting and running of a second motor-compressor or group of motorcompressors, the conductor size shall be determined from the largest motor-compressor or group of motor-compressors that is to be operated at a given time. Exception No. 2: Room air conditioners as provided in Part G of Article 440. 440-34. Combination Load. Conductors supplying a motor-compressor load in addition to a lighting or appliance load as computed from Article 220 and other applicable articles shall have an ampacity sufficient for the lighting or appliance load plus the required ampacity for the motorcompressor load determined in accordance with Section 440-33, or, for a single motor-compressor, in accordance with Section 440-32. Exception: Where the circuitry is so interlocked as to prevent simultaneous operation of the motor-compressor(s) and all other loads connected, the conductor size shall be determined from the largest size required for the motor-compressor(s) and other loads to be operated at a given time. 440-35. Multimotor and Combination-Load Equipment. The ampacity of the conductors supplying multimotor and combination-load equipment shall not be less than the minimum circuit ampacity marked on the equipment in accordance with Section 440-4(b). E. Controllers for Motor-Compressors 440-41. Rating. (a) Motor-Compressor Controller. A motor-compressor controller shall have both a continuous-duty full-load current rating, and a locked-rotor current rating, not less than the nameplate rated-load current or branchcircuit selection current, whichever is greater, and locked-rotor current, respectively (see Sections 440-6 and 440-7) of the compressor. In case the motor controller is rated in horsepower, but is without one or both of the foregoing current ratings, equivalent currents shall be determined from the ratings as follows: use Table 430-148, 430-149, or 430-150 to determine the equivalent full-load current rating. Use Table 430-151 to determine the equivalent locked-rotor current ratings. (b) Controller Serving More than One Load. A controller, serving more than one motor-compressor or a motor-compressor and other loads, shall have a continuous-duty full-load current rating, and a locked-rotor current rating not less than the combined load as determined in accordance with