Their dimensions are generally around 2 inches wide by 4 inches tall, with depths varying from 1-1/2 inches to 3-1/2 inches. Typically available in depths ranging from 1-1/2 inches to 2-1/8 inches, their square shape provides ample internal volume for making multiple wire connections and housing various types of wiring devices when used with appropriate covers. Their size makes them suitable for situations where several. 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. NEC Article 314. These requirements apply to conductors 4 AWG and larger. Common uses: wall outlets, light switches, low-voltage controls. Junction boxes must be made of non-combustible material, such as metal or plastic. But it is still a good practice to always keep in mind to carefully bend.
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