- #Plaster rings and domed coveres full
- #Plaster rings and domed coveres code
- #Plaster rings and domed coveres plus
Unfortunately, all too often, electricians remove junction box covers only to find the box crammed full of conductors. Some creative methods have been devised to overpack the conductors into a junction box so that the cover can still be installed. Such methods include, but are not limited to: carefully wrapping the conductors around the inside of the box so that no air space remains mashing the conductors down with the thumb, the heel of the hand or even by applying force with the handle of a hammer.
An optional creative method is to back out the junction box screws, insert a blank plate, then tighten the screws, thereby compressing the conductors. Of course, not one of these methods is correct.
#Plaster rings and domed coveres code
Article 370 contains detailed requirements for box fill and junction box sizing.Īrticle 370 of the National Electrical Code (NEC) covers a variety of provisions pertaining to boxes (outlet, device, pull junction), conduit bodies, and fittings.
It covers the installation and use of all boxes (and conduit bodies) used as outlet, junction, or pull boxes, depending on their use. It also covers manholes (including other electric enclosures intended for personnel entry). Manholes and Other Electric Enclosures Intended for Personnel Entry (new to the 1999 edition), and E. Pull and Junction Boxes for Use on Systems Over 600 Volts, Nominal. This month's In Focus discusses Installation (Part B).ģ70-15 Damp, Wet, or Hazardous (Classified) Locationsīoxes, conduit bodies, and fittings in damp or wet locations must be placed or equipped so as to prevent the entrance of, or internal accumulation of, moisture. Damp locations, as defined in Article 100, are locations subject to moderate degrees of moisture. If a receptacle has 12 AWG wire connected to it, a volume allow-ance of 2 x 2.25 or 4.5 cubic inches must be made for that particular device.Partially protected external locations under canopies, marquees, roofed (open) porches, and similar sites are considered damp locations as are some interior locations such as certain basements, barns, and cold-storage warehouses. For example, if a switch has 14 AWG conductors connected to it, a volume allowance of 2 x 2.0 cubic inches or 4 cubic inches is required. Each device or equipment is considered individu-ally where more than one item is contained in the box. This volume allowance is based on the largest conductor connected to a device(s) or equip-ment supported by that yoke or strap. Table 314.16(B) gives the volume allowance. A double volume allow-ance is required for each yoke or strap containing one or more devices or equipment. Minimum requirements for device or equipment fill are also provided in the Code. So the Code assigns to each conductor, clamp, support fitting, device and equipment grounding conductor an associated volume allowance. June 2012 Box Fill Calculations for Switch Boxes take up space within the box. Conductors, internal clamps, sup-port fittings, and devices such as switches and receptacles 74 IAEI NEWS May. This total volume (space) determines the number and size of conductors and wiring devices permitted to be contained in the box.
#Plaster rings and domed coveres plus
Total volume is the volume of the box plus the volume of any attached plaster rings, extension rings, or domed cover. If the extension ring is made of metal and corresponds to a size listed in NEC Table 314.16(A), the appropriate volume for that size box is used as the volume of the extension ring. Where used, the space provided by plaster rings, domed covers and extension rings that are marked with their volume in cubic inches is included. Volume of a box is the total volume in cubic inches of the assembled sections. This sufficient space is needed to allow proper dissipation of heat from the contained conductors with proper air flow and circulation around the conductors. Switch boxes and other device boxes must have ade-quate volume of space (cubic inches) in order to contain the required conductors and devices (switches, etc.) to be enclosed in said box. Spare switched conductors at ceiling box will requires ceiling fan support box. International Association of Electrical Inspectors May/June 2012:
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