Off-grid component requirements
ACDB / DCDB Protection
Electrical protection on DC and AC sides.
ACDB and DCDB panels organize isolators, fuses, MCBs, SPDs and other protection devices so faults can be isolated and equipment can be maintained safely.
Role in the System
Protects PV strings and inverter circuits.
Provides isolation for service and emergency shutdown.
Reduces risk from short circuit, overload and surge events.
Sizing Checks
PV string current and voltage.
Inverter input/output ratings.
MCB, fuse and isolator ratings.
Surge protection requirement.
Indoor/outdoor enclosure IP rating.
Required Documents
Protection device schedule.
AC/DC single-line diagram.
DB enclosure specification.
Fuse/MCB/SPD datasheets.
Commissioning test report.
Safety Checks
Correct polarity and terminal labeling.
DC-rated devices on DC side.
SPD and earthing connection.
Cable gland and enclosure sealing.
Clear circuit identification labels.
Handover Records
Final SLD.
Protection rating list.
DB photos and labels.
Shutdown and isolation procedure.
Maintenance Notes
Inspect DB for heat marks, water entry or loose terminals.
Test isolation procedure during maintenance.
Replace surge devices if indication shows failure.