Panels and batteries can supply dangerous current even when utility power is off. Protection equipment is not an optional extra: it provides safe isolation, limits fault current and reduces damage from surges and wiring faults.
DC protection between panels and inverter
Solar strings need devices rated for the system’s DC voltage and current. Ordinary AC breakers may not safely interrupt a DC arc. Combiner boxes can bring together string fuses, breakers, surge protection and isolation.
- Correctly rated PV string fuses where required
- DC isolator accessible for maintenance
- DC surge-protection device with short earth path
- UV-resistant solar cable and compatible connectors
Battery and AC protection
A battery fuse or breaker should be installed close to the battery and sized for the cable and maximum current. The inverter output also requires suitable AC isolation, over-current protection and earth-leakage protection where applicable.
- Battery fuse or DC breaker
- AC input and output breakers
- Changeover or bypass arrangements designed safely
- Correct cable termination and enclosure protection
Earthing and surge paths
Protection devices only work correctly when installed as a coordinated system. Panel frames, equipment cases and surge devices need an earthing design suited to the building and local conditions.
Final takeaway
Ask for protection devices to be listed clearly in every quotation. Safe isolation, correct ratings and quality installation protect both the investment and the people using it.
