plaster rings to increase number of conductors

Plaster rings to increase number of conductors for free#
Plaster rings to increase number of conductors install#

Boxes may be fastened to structural members of a building. Boxes may be fastened to a surface that provides adequate support. Securely support boxes by one of the following methods : The continuity of the equipment grounding conductor must be maintained independently of the connection between the box and the cover so that this connection will not be interrupted when removing the box cover ( Fig. A surface extension can be made from a box cover only if the extension is a flexible wiring method that will permit the removal of the cover and provide access to the box interior. Correctly sized openings can be made by using templates or similar means to help reduce this type of repair work.Ī surface extension can be made to a flush covered box by mounting an extension ring over it. The NEC requires that oversized, uneven holes around a flush box be repaired so that the gap around a flush-covered box is a maximum of 1⁄8 in. Plaster rings and extension rings are available in a variety of depths to meet these requirements. Combustible, ensure the front edge is flush with, or sticks out from, the finished surface.Noncombustible, ensure the front edge of the box, plaster ring, extension ring, or listed extender is no more than 1⁄4 in.

Plaster rings to increase number of conductors install#

Recessed boxesĭepth limits apply when you install boxes with flush-type covers into recesses of walls or ceilings. įasten raceways and cables to boxes or conduit bodies by fittings designed for the wiring method. The means of closing these openings must provide protection that is substantially equivalent to the equipment wall. Openings through which conductors enter must be adequately closed. Splices are only allowed in a conduit body when the manufacturer has stamped the allowable volume marking on the conduit body. Table 314.16(B) also limits the number of splices permitted in a conduit body. Raceway and cable fittings, including locknuts and bushings.Cable connectors that have their clamping mechanism outside of the box.Equipment grounding conductors, and up to four 16 AWG or smaller fixture wires that enter the box from a domed luminaire or similar canopy such as a ceiling paddle fan canopy.Conductors that originate and terminate within the box, such as pigtails.

Multigang device yoke (for each gang required for mounting), based on the largest conductor that terminates on the device ( Fig.

Single-gang device yoke (regardless of the ampere rating), based on the largest conductor that terminates on the device.

Plaster rings to increase number of conductors 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.