What switch should be connected to the distribution box

A double pole MCB (Miniature Circuit Breaker) or main isolator switch is used to connect the distribution box to the incoming power supply.

Main Switch Function

The main switch, also called the main isolator or main breaker, is installed at the entry point of the distribution box. It controls the entire electrical supply to the board, allowing you to safely disconnect all power during maintenance or emergencies . In single-phase residential systems, this is typically a double pole MCB, which simultaneously isolates both the live (phase) and neutral lines . For three-phase systems, a three-pole MCB or isolator is used.

Additional Protective Devices

After the main switch, the power is usually routed through RCCBs (Residual Current Circuit Breakers) or RCDs (Residual Current Devices) to protect against leakage currents and electric shocks . Individual circuits are then protected by single pole MCBs for overcurrent protection, ensuring that each subcircuit can be safely isolated if needed .

Summary of Connections

1. Incoming power from the utility or transformer enters the distribution box.
2. Main switch (double pole MCB or isolator) connects and disconnects the entire supply.
3. RCCB/RCD provides leakage protection.
4. Single pole MCBs distribute power to individual circuits.
5. Busbars, neutral links, and earth bars ensure proper distribution and grounding . Using a double pole MCB or main isolator ensures that the distribution box can be safely connected and disconnected, providing both operational control and safety for the entire electrical system.