This will be all new construction. We are putting light pole fixtures on top of a bridge parapet wall. Below each pole fixture we are putting a Pull/Junction Box with cover plate in the parapet wall. The question is how big does the box need to be ? We want to minimize the size but it must comply with NEC. Each box will have 2 #4/0 + ground wire in a 3" horizontal conduit entering and the same exiting the box. Inside the box 2 # 10 + ground will be spliced with the # 4/0 + ground wires and the # 10 + ground will exit the top of the box in a 1.25" conduit to feed the light pole on top of the parapet wall. What is the minimum size ( length X width X depth) box we can use that will meet NEC ? Thank You
