Standard rectangular boxes typically have mounting holes spaced $3. 5$-inch center-to-center spacing, depending on the box diameter. Precise measurement is necessary, as misalignment prevents the cover from. Wall plates available on DataPro's Plate Creator use Box Mount screw hole spacing of 3. Note that for measuring purposes, distances are measured from center to center. Box. The screw hole spacing is the critical factor for plate selection, as it must align precisely with the mounting points on the box or device. Dimensions for faceplates and other electrical devices are covered by ANSI/NEMA WD 6, Wiring Devices - Dimensional. Within electrical installations regulated by NEC and UL standards, the terminology surrounding junction boxes extends well beyond simple measurements of length and width. Choosing the proper enclosure requires fluency in the language of gangs, physical footprint, and—most importantly— internal. The screw spacing is 3. The plate screws into a device strap.
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