PV systems that have three or more strings connected in parallel need to have each string protected by fuses. Systems that have less than three strings will not generate enought fault current to damage the conductors/solar panels. Normaly there are two gPV fuses connected on each string (+ and - pole), that protect conductors/solar panels from damage and eliminate any safety hazards. Fuses isolate the faulted string. The rest of PV system can continue to generate electricity.