Pull boxes shall be installed in conduits at an interval no greater than every 100 feet. The parameters are 3x500kcmil 1/C 2. 4kV Okonite cables run in 4" PVC that transitions to RTRC for the final stub up. The full cable length from the disconnect to the feed point is approx 1800' with two manholes within that length. Bends are all fairly large but I can't determine exact degrees of. Choose the right box based on environment (indoor/outdoor), load capacity, and durability. Practice good wiring: secure. A distribution box, also known as a power distribution box or electrical distribution box, is used to distribute electrical power safely to multiple circuits. Safety is the top priority when choosing a distribution box.