Solar ACDB vs DCDB: What Is the Difference?

Where each board is installed

The typical path is PV strings → DCDB or inverter-integrated DC protection → inverter → ACDB → main distribution or grid connection. The exact arrangement depends on inverter design and the approved project diagram.

Compare the protection

DC circuits require equipment suitable for sustained DC arcs and the array voltage. AC circuits require devices suited to AC voltage, frequency and prospective fault current. Neither board replaces inverter anti-islanding functions or all upstream protection.

Practical project example

On a commercial rooftop, PV strings connect to the inverter DC inputs while the inverter AC output connects to the building distribution. Specify protection for each side separately; an AC-rated protective device is not automatically suitable for the DC circuit.

Selection checklist

For a DCDB, check cold-weather string voltage, string current and MPPT routing. For an ACDB, check inverter output current, phases, feeder size, fault level, isolation and surge coordination. Never substitute an AC breaker for a DC-rated device.

Frequently asked questions

Can AC and DC protection devices be interchanged?

No. Each device must be suitable for the circuit voltage, current type and interruption duty. A combined enclosure does not make devices interchangeable.

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 Dcdb
• Solar Acdb
• Solar Dc Distribution Boxes