ACDB is an important part of SPV system. It gives protection to the system in case of failures on load side. ACDB is made up of breakers, isolators, voltage and current monitoring devices etc. To ensure maximum protection to the sophisticated electronic equipment, It has provision for surge protection in addition to fuses. Also, ACDBs consists of energy meter which helps to know how much solar energy is being utilised.

Solar DCDB protects the SPV system, if there is any fault on DC side. The DCDB constitutes: isolator/breaker-to switch off the system during a fault; panel meters - to give PV array voltage and current readings, and it comprises surge protection device.