Use the ATS (Automatic Transfer Switch) for automatic switching between two power sources:

             • One source = Mains power     • One source = PV system (inverter output)

The ATS automatically selects the normal and priority power source, ensuring uninterrupted power supply, no conflict, and no back-feeding.

1. Wiring Connection for PV ATS (Simplest Standard Solution)

              1. PV panels → PV inverter → Output 220V/380V

             2. Inverter output → Connect to the backup power terminal of ATS

             3. Mains power → Connect to the common power terminal of ATS

             4. ATS output → Connect to home/equipment/distribution box load

3. Working Modes

Mode 1: Daytime with sufficient sunlight → Priority to PV power

          • PV inverter generates power normally with stable voltage

          • ATS automatically switches to PV power supply

          • Load runs entirely on solar power, no mains power consumed, saving electricity and cost

Mode 2: Nighttime/Cloudy day/PV failure → Automatic switch to mains power

          • PV stops generating power or voltage is abnormal

          • ATS automatically switches back to mains power in milliseconds

          • Equipment runs continuously 

Mode 3: Automatic switch-back

          When mains power or PV power recovers, the ATS will switch back automatically.
          The whole process is fully automatic without manual operation.

4. Advantages of This Combination

          • Use solar power whenever available to reduce electricity costs.

          • Automatic switch to mains power when solar power is unavailable, ensuring uninterrupted power.

          • Safe: No back-feeding, protects PV system and electricians.

          • Fully automatic, no on-duty personnel required.

          • Suitable for households, factories, farms, shops, etc.

5. Critical Safety Notes (Very Important)

            1. The PV inverter must support off-grid/uninterrupted output. Ordinary grid-tie inverters are not applicable (will trip).

            2. The ATS must be a qualified product with interlock and anti-back-feeding functions.

            3. Direct parallel connection of PV and mains power is strictly prohibited. Switching must be done via ATS.

            4. Power matching: ATS rated current ≥ Inverter output current

6. Simple Summary

The PV inverter serves as one power source, and mains power as the other.
The ATS automatically detects available power and switches the supply accordingly.
Use solar power during the day and grid power at night, fully automatic and uninterrupted.