CRANES AND HOISTS

A. General 610-1. Scope. This article covers the installation of electric equipment and wiring used in connection with cranes, monorail hoists, hoists, and all runways. (FPN): For further information, see Safety Code for Cranes, Derricks, Hoists, Jacks, and Slings, (ANSI B-30). 610-2. Special Requirements for Particular Locations. (a) Hazardous (Classified) Locations. All equipment that operates in a hazardous (classified) location shall conform to Article 500. (1) Equipment used in locations that are hazardous because of the presence of flammable gases or vapors shall conform to Article 501. (2) Equipment used in locations that are hazardous because of combustible dust shall conform to Article 502. (3) Equipment used in locations that are hazardous because of the presence of easily ignitible fibers or flyings shall conform to Article 503. (b) Combustible Materials. Where a crane, hoist, or monorail hoist operates over readily combustible material, the resistors shall be placed in a well-ventilated cabinet composed of noncombustible material so constructed that it will not emit flames or molten metal. Exception: Resistors shall be permitted to be located in a cage or cab constructed of noncombustible material that encloses the sides of the cage or cab from the floor to a point at least 6 inches (152 mm) above the top of the resistors. (c) Electrolytic Cell Lines. See Section 668-32. B. Wiring 610-11. Wiring Method. Conductors shall be enclosed in raceways or be Type MC cable or Type MI cable. Exception No. 1: Contact conductors. Exception No. 2: Short lengths of open conductors at resistors, collectors, and other equipment. Exception No. 3: Where flexible connections are necessary to motors and similar equipment, flexible stranded conductors shall be installed in flexible metal conduit, liquidtight flexible metal conduit, multiconductor cable, or an approved nonmetallic enclosure. ARTICLE 610 - CRANES AND HOISTS 70-645 Exception No. 4: Where multiconductor cable is used with a suspended pushbutton station, the station shall be supported in some satisfactory manner that protects the electric conductors against strain. Exception No. 5: Where flexibility is required for power or control to moving parts, a cord suitable for the purpose shall be permitted provided: a. Suitable strain relief and protection from physical damage is provided; and b. In Class 1, Division 2 hazardous locations, cord shall be approved for extra-hard usage. 610-12. Raceway or Cable Terminal Fittings. Conductors leaving raceways or cables shall comply with one of the following: (a) Separately Bushed Hole. A box or terminal fitting having a separately bushed hole for each conductor shall be used wherever a change is made from rigid metal conduit, intermediate metal conduit, electrical metallic tubing, metal-clad cable, mineral-insulated cable, or surface raceway wiring to open wiring. A fitting used for this purpose shall not contain taps or splices and shall not be used at fixture outlets. (b) Bushing in Lieu of a Box. A bushing shall be permitted to be used in lieu of a box at the end of a rigid metal conduit, intermediate metal conduit, or electrical metallic tubing where the raceway terminates at unenclosed controls or similar equipment including contact conductors, collectors, resistors, brakes, power circuit limit switches, and dc split frame motors. 610-13. Types of Conductors. Conductors shall comply with Table 310-13. Exception No. 1: Conductor(s) exposed to external heat or connected to resistors shall have a flame-resistant outer covering or be covered with flame-resistant tape individually or as a group. Exception No. 2: Contact conductors along runways, crane bridges, and monorails shall be permitted to be bare, and shall be copper, aluminum, steel, or other alloys or combinations thereof in the form of hard drawn wire, tees, angles, tee rails, or other stiff shapes. Exception No. 3: Flexible conductors shall be permitted to be used to conduct current and, where practicable, cable reels or take-up devices shall be used. 610-14. Rating and Size of Conductors. (a) Ampacity. The allowable ampacities of conductors shall be as shown in Table 610-14(a). (FPN): For the ampacities of conductors between controllers and resistors, see