How to size a solar ACDB
What an ACDB does in a solar plant and how to choose its breaker, SPD and metering for a rooftop system.
What the ACDB does
The AC distribution box sits between the inverter and the building's distribution or grid connection. It isolates the inverter, protects the AC cable and gives a safe point to disconnect the plant.
Step 1: inverter AC current
Divide the inverter's AC output by the voltage (230 V single phase, or 1.732 x 415 V for three phase). Our selection table does this for common sizes.
Step 2: incomer breaker
Choose a breaker rated about 125% of the inverter's rated AC current, rounded to the next standard size, with a breaking capacity above the fault level at the point of connection.
Step 3: surge protection and metering
Add an AC surge protective device and provision for the meter or energy monitoring that the utility or the owner requires.
Step 4: enclosure
Choose the enclosure for the site: polycarbonate for small outdoor boxes, painted mild steel for larger ratings, with the ingress protection the location needs.
Send us the SLD
Share the inverter make and rating, number of inverters and site fault level. We reply within one working day.
Send us your requirement
Attach the SLD, BOQ or site details. We reply on enquiries within one working day.