OVERCURRENT PROTECTION

240-1. Scope. Parts A through G of this article provide the general requirements for overcurrent protection and overcurrent protective devices not more than 600 volts, nominal. Part H covers overcurrent protection over 600 volts, nominal. (FPN): Overcurrent protection for conductors and equipment is provided to open the circuit if the current reaches a value that will cause an excessive or dangerous temperature in conductors or conductor insulation. See also Sections 110-9 and 110-10 for requirements for interrupting capacity and protection against fault currents. A. General 240-2. Protection of Equipment. Equipment shall be protected against overcurrent in accordance with the article in this Code covering the type of equipment as specified in the following list. ARTICLE 240 - OVERCURRENT PROTECTION 70-91 Article Air-Conditioning and Refrigerating Equipment 440 422 Appliances 210 Branch Circuits 364 Busways 460 Capacitors Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power- 725 Limited Circuits Closed-Loop and Programmed Power Distribution 780 Cranes and Hoists 610 Electric Signs and Outline Lighting 600 630 Electric Welders 668 Electrolytic Cells Elevators, Dumbwaiters, Escalators, Moving Walks, Wheelchair Lifts, and Stairway Chair Lifts 620 700 Emergency Systems Fire Protective Signaling Systems 760 Fixed Electric Heating Equipment for Pipelines and Vessels 427 Fixed Electric Space Heating Equipment 424 Fixed Outdoor Electric Deicing and Snow-Melting Equipment 426 445 Generators Health Care Facilities 517 Induction and Dielectric Heating Equipment 665 670 Industrial Machinery Lighting Fixtures, Lampholders, Lamps, and Receptacles 410 Motion Picture and Television Studios and Similar Locations 530 Motors, Motor Circuits, and Controllers 430 455 Phase Converters 650 Pipe Organs 518 Places of Assembly 230 Services Solar Photovoltaic Systems 690 Sound-Recording and Similar Equipment 640 Switchboards and Panelboards 384 Theaters, Audience Areas of Motion Picture and Television Studios, and Similar Locations 520 Transformers and Transformer Vaults 450 660 X-Ray Equipment 240-3. Protection of Conductors. Conductors, other than flexible cords and fixture wires, shall be protected against overcurrent in accordance with their ampacities as specified in Section 310-15, unless otherwise permitted in (a) through (m) below. (a) Power Loss Hazard. Conductor overload protection shall not be required where the interruption of the circuit would create a hazard, such as in a material handling magnet circuit or fire pump circuit. Short-circuit protection shall be provided. 70-92 NATIONAL ELECTRICAL CODE (FPN): See Installation of Centrifugal Fire Pumps, NFPA 20 - 1990 (ANSI). (b) Devices Rated 800 Amperes or Less. Conductors not part of a multioutlet branch circuit supplying receptacles for cord- and plug-connected portable loads and where the ampacity of the conductors does not correspond with the standard ampere rating of a fuse or a circuit breaker without overload trip adjustments above its rating (but that may have other trip or rating adjustments), the next higher standard device rating shall be permitted only if this rating does not exceed 800 amperes. (c) Devices Rated Over 800 Amperes. Where the overcurrent device is rated over 800 amperes, the ampacity of the conductors it protects shall be equal to or greater than the rating of the overcurrent device as defined in