Box-Fill Calculations, Part IX

摘要

Section 314.1 covers the scope of Article 314. This article covers the installation and use of all boxes and conduit bodies used as outlet, device, junction or pull boxes, depending on their use. In the 2002 edition of the National Electrical Code, manholes and other electric enclosures intended for personnel entry were in Article 314. In the 2005 edition, provisions pertaining to manholes and other electric enclosures intended for personnel entry were moved to Article 110, Part V. New specifications for handhole enclosures, an addition to Article 314 in the 2005 Code, are in 314.30. The last sentence in the scope of Article 314 states that the article also includes installation requirements for fittings used to join raceways and to connect raceways and cables to boxes and conduit bodies. Specifications for calculating the number of conductors in outlet, device and junction boxes and conduit bodies are in 314.16. While box-volume calculations are in 314.16(A), box-fill calculations are 314.16(B). Last month's "Code in Focus" concluded with equipment-grounding conductor fill in 314.16(B)(5). This month, the discussion begins with conduit bodies in 314.16(C).