The main distribution box shall be located in the area close to the power supply; the distribution box shall be installed in the area with relatively concentrated electrical equipment or load; the distance between the distribution box and the switch box shall not. The main distribution box shall be located in the area close to the power supply; the distribution box shall be installed in the area with relatively concentrated electrical equipment or load; the distance between the distribution box and the switch box shall not. The main distribution box (or distribution room) shall be set up. The distribution box shall be set below the main distribution box, and the switch box shall be set below the distribution box, and the electrical equipment shall be set below the switch box. The main distribution board. Clause 2. If not correctly arranged the service protection device (SPD) can be. Proper construction techniques are essential for the protection and durability of electrical systems. Covers wiring, placement, standards, and expert tips for a compliant setup.