#JUNCTION BOX VOLUME WITH PLASTER RING FOR FREE#
Loop or coil of unbroken conductor having a length at least twice the minimum length required for free conductors in 300.14 ( Fig.Equipment grounding conductors, based on the largest equipment grounding conductor that enters the box.Each luminaire stud or hickey, based on the largest conductor that enters the box.One or more internal cable clamps, based on the largest conductor that enters the box.Any conductor that runs through, or terminates in, a box.When counting conductor volumes, calculate each one per Table 314.16(B). This will give you the total volume of the conductors, devices, and fittings. Size conduit bodies per 314.16(C) and handhole enclosures per 314.30(A). The volume of the box as calculated in 314.16(A) must not be less than the volume requirement calculated in 314.16(B). If boxes contain 6 AWG and smaller conductors, size them per 314.16 to provide sufficient free space for their contents. That includes plaster rings, extension rings, and domed covers that are either marked with their volume in cubic inches (cu in.) or made from boxes listed in Table 314.16(A). The volume of a box includes the total volume of its assembled parts. Conductors, splices, and terminations installed inside handhole enclosures must be listed as suitable for wet locations. Parts installed in damp or wet locations must be listed for such locations.
Installationīoxes and conduit bodies in damp or wet locations must prevent moisture from entering or accumulating within the enclosure.
įor this same reason, metal boxes must be connected to an equipment grounding conductor of a type listed in 250.118, if the circuit they enclose operates at 50V or more. This rule is essential in order to maintain the electrical continuity of the effective ground-fault current path required for metallic cables and raceways. However, to use them with metallic cables and raceways, an internal bonding means must be provided between all metal parts. These rules can seem arbitrary, but there really is logic behind them.įor example, nonmetallic boxes can be used with nonmetallic cables and raceways. Article 314 contains installation requirements for outlet and pull boxes, junction boxes, conduit bodies, and handhole enclosures.
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