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

1. Main MCB (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 .
2. RCCB / 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 .
3. Output MCBs (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 .
4. Neutral Link / Busbar
   • A 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 .
5. Earth Link / Busbar
   • Provides 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 → Loads
• Neutral wire → Neutral link → Loads
• Earth wire → Earth link → Loads

Color Coding and Safety

• Phase (Live): Red or brown
• Neutral: Black or blue
• Earth: Green/yellow
• Ensure all connections are tight, and the power supply is turned off before wiring .

Visual Representation

A simplified terminal arrangement diagram:

Incoming 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 .