Solar system with generator: how it works

1. When you need it

In periods with little sun, especially in winter, the panels may not be enough. The generator starts, charges the battery and powers the house, then stops. So the system stays independent even without the grid.

2. GEN input and dry contact

The Growatt has a dedicated generator input (GEN). Its dry contact can start a generator with automatic start when the battery drops below a threshold, and stop it when charged. While the generator runs, the Growatt charges the battery and powers the house.

The dry contact is a command: it tells the generator to start, it does not power the starter motor. You need a generator with automatic start and a compatible interface.

3. The 1-0-2 switch

The manual 1-0-2 changeover switch is for emergencies: in position 1 the house runs on the Growatt (normal), in 2 directly on the generator, if the Growatt is stopped. Position 0 disconnects everything. It can never connect both sources together.

4. Thresholds and settings

Start and stop thresholds, charging current and generator power must respect the Growatt and generator manuals. Settings for the CEG Growatt are provided by Carmine.

5. Mistakes to avoid

• Thinking the dry contact can power the starter motor.
• A generator too small for charging and for the house's starting currents.
• Connecting the generator anywhere other than the GEN input without a switch that separates the sources.

6. The detailed wiring diagram

The block diagram helps you understand how it works. The detailed wiring diagram, with terminals and connections, is reserved for those who bought through Carmine Energia Gratis: write to Carmine with your CEG pre-order number. Wiring and testing must be done by a qualified electrician.

Ask for the detailed diagram All CEG diagrams

7. Frequently asked questions