Wiring diagram of distribution box terminal

A typical single-phase distribution box arranges the main MCB, RCCB, output MCBs, neutral link, and earth link in a structured sequence to safely distribute power to multiple circuits.

Key Components and Terminal Arrangement

Main MC

B (Double Pole)Acts as the main switch controlling the entire supply. The incoming phase (live) and neutral wires from the energy meter are connected to the input terminals of the main MCB. Output terminals feed the RCCB or directly to the busbars for distribution.

RCC

B / RCD (Double Pole)Provides protection against leakage currents, electrical shocks, and insulation faults. The input terminals of the RCCB are connected to the output of the main MCB. The output terminals supply the single-pole MCBs for individual circuits.

Output MC

Bs (Single Pole or Double Pole)Each MCB protects a specific load or circuit (e.g., lights, fans, sockets). The phase wire from the RCCB output is connected to the input of each MCB. The neutral wire of each load is connected to the neutral link.

Neutral Link / BusbarA common terminal strip distributing neutral to all output circuits. Connected to the neutral output of the RCCB and to the neutral wires of all loads. Earth Link / BusbarProvides grounding for safety.

All earth wires from the supply and connected loads are terminated here and linked to the building's earth electrode.

Wiring Flow Summary

Incoming supply → Main MCB → RCCB → Output MCBs → LoadsNeutral wire → Neutral link → LoadsEarth wire → Earth link → LoadsColor Coding and SafetyPhase (Live): Red or brownNeutral: Black or blueEarth: Green/yellowEnsure all connections are tight, and the power supply is turned off before wiring.

Visual Representation

A simplified terminal arrangement diagram: CodeCopyIncoming Supply L ──> Main MCB ──> RCCB ──> Output MCBs ──> Loads N ──> Main MCB ──> RCCB ──> Neutral Link ──> Loads E ─────────────────────────> Earth Link ──> Loads This layout ensures safe distribution, proper protection, and easy maintenance. For more detailed diagrams, including specific MCB ratings and RCD connections, refer to single-phase distribution box wiring guides.