314.16 Number of Conductors in Outlet, Device, and Junction Boxes, and Conduit Bodies The National Electrical Code has specific requirements detailing how to calculate the maximum number of conductors in boxes (outlet, device, junction, etc.) and conduit bodies.
Jim Dollard has an extensive background in codes and standards. If you have a query about the National Electrical Code (NEC), Jim will help you solve it. Questions can be sent to firstname.lastname@example.org. Answers are based on the 2014 NEC. Pull boxes for communications cable