The National Electrical Code (NEC) rules for the aforementioned are in Sec. 314.28. But don’t confuse them with outlet boxes [314.27(A) through (E)]. The rules for pull boxes, junction boxes, and ...
Pull boxes, junction boxes, and conduit bodies must be sized to allow conductors 4 AWG and larger to be installed without damage to the conductor insulation. The NEC provides sizing requirements in ...