The distribution board (DB) is the heart of a home’s wiring — it splits the incoming supply into protected circuits. A well-planned DB is what makes fault-finding easy and keeps the house safe.
Core components
- Main switch / isolator — cuts the whole supply.
- RCCB (or RCBO) — trips on earth-leakage to prevent shock.
- MCBs — one per circuit, rated to that circuit’s wire size.
Separate the circuits
Split the load into logical circuits — lighting, general sockets, kitchen, air-conditioners, geyser — each on its own MCB and correctly-sized cable. High-load appliances always get a dedicated circuit so they never share with lights or general sockets.
Balance the load
On a three-phase supply, spread circuits as evenly as possible across the three phases so no single phase is overloaded. Label every MCB clearly, and make sure each MCB rating matches the cable it protects — never fit a larger MCB to “stop nuisance tripping.”
Indicative guidance for typical Indian domestic installations. Always confirm final cable sizes against the applicable IS standards, your local wiring rules and a licensed electrician for your specific installation.