Automatic changeover switch setup

This is a simplified and easy-to-understand layout of a residential power backup system using an automatic changeover switch (ATS). The setup is designed to automatically switch the power supply between the utility grid (from the transformer) and a diesel generator (DG set) in case of a power outage.

Starting from the top-right, the transformer brings electricity from the grid (utility supply). It is connected to one side of the automatic changeover switch, supplying the normal (grid) input. On the left side, the DG set (diesel generator) is connected, serving as the backup power source. These two inputs are wired into the automatic transfer switch (ATS), which intelligently selects the available source.

The automatic changeover switch (ATS) is the brain of this setup. When the grid supply from the transformer is available, it allows that power to pass through to the house. But if the grid supply fails, it detects the failure and automatically switches to the generator, assuming the DG is turned on or starts automatically. Once the grid is restored, the ATS shifts back to grid power. This switching helps avoid manual intervention and ensures an uninterrupted supply.

Below the changeover switch, the output power is routed through an MCB (Miniature Circuit Breaker) before entering the house. The MCB provides overcurrent protection, preventing electrical fires or damage to wiring and appliances due to short circuits or overloads. From the MCB, power is safely distributed to the house’s internal wiring, sockets, and appliances.

In summary, this system ensures that the home always receives power either from the grid or the generator with automatic switching, and it also includes basic protection via the MCB to safeguard the house's electrical infrastructure.