How to Select ACDB and DCDB for a Solar Inverter

Start with the inverter inputs

Record maximum DC voltage, MPPT operating range, maximum input current and short-circuit current per input. Check cold-weather PV string voltage and the permitted parallel string arrangement. Inverter integrated protection can affect the need for external devices, so inspect the manufacturer wiring instructions.

Size the AC distribution circuit

Use maximum inverter output current, phase arrangement and nominal AC voltage. Select cable capacity and protection together, allowing for installation conditions. Confirm the prospective fault level and upstream protection coordination rather than sizing the ACDB only from PV kWp.

A practical comparison

For illustration, two 10 kW inverters may require two independently protected incoming AC feeders and a common outgoing circuit. Their DC strings still follow each inverter MPPT layout. This example describes topology, not a recommended breaker rating.

Prepare the procurement schedule

List PV string circuits, DC voltage limits, inverter AC outputs, isolation points, surge protection, earthing, enclosure environment and cable entries. Request an approved schematic and component schedule for both boards before purchase.

Frequently asked questions

Can I select an ACDB by solar plant kWp alone?

No. Inverter AC output current, phases, fault level, cable capacity and the protection arrangement determine the required configuration.

Are the examples a GEESYS product specification?

No. Worked examples explain selection principles. Use the selected product datasheet and approved project design for actual ratings and installation requirements.

Related GEESYS products

• Solar Acdb
• Solar Dc Distribution Boxes