Connect the phase and neutral wires from the input power supply to the input of the Main MCB. Learn how to wire a distribution box step by step! This video shows real on-site footage of electrical installation, demonstrating safe and standardized wiring methods used by professionals. These smaller distribution centers are designed to take power from a larger main service panel and distribute it locally to. Connection method: Each switch takes a wire from the incoming point and connects it to the incoming end of the switch, or uses parallel connection to reduce the difficulty of wiring. In this guide, we'll break down everything you need to know to install a distribution box correctly and confidently. Check for proper IP/NEMA ratings and material quality.