Fuse standards: gPV + Current + Voltage (Source: Synode); Golden Rule: Use gPV, not gG (Source: SurgePV); Core Requirement: 1.56 × Isc (Source: NEC); Note: Breaking capacity of 30kA (Source: Kuangya).
I.
gPV Category
gPV: Fuse category specific to photovoltaics (Source: Kuangya); IEC: IEC 60269-6 standard (Source: Kuangya); UL: UL 248-19 / UL 2579 (Source: SurgePV); Distinction: Not gG or gL (Source: Synode); Time-Current Characteristic: Withstands irradiance fluctuations (Source: Kuangya) — Category: gPV + IEC + UL (Triple certification).
II.
Rated Current
1.56x: 1.56 × Isc per NEC 690.9 (Source: VIOX); Calculation: 10A Isc → 15.6A → Select 16A (Source: Synode); 1.25: 1.25 × Isc lower limit (Source: Lawson); Derating: ×0.85 at 60°C ambient temperature (Source: Synode); Reverse Current: Interrupts maximum reverse current (Source: Lawson) — Current: 1.56 + 1.25 + Derating (Three rules).
III. Rated Voltage
1.25x: Voltage ≥ 1.25 × Voc (Source: Synode); Rating: 1000V/1500V DC (Source: Synode); Prohibition: 600V fuses must not protect 1000V systems (Source: CNLONQ); Matching: Match system voltage class (Source: Lawson); Standard: gPV rated for 1500V DC (Source: Kuangya)—Voltage: 1.25x + Rating + Matching (Three key points).
IV.
Breaking Capacity
30kA: Cylindrical gPV breaks 30kA (Source: Kuangya); 50kA: DC breaking capacity of 50kA (Source: LSP); Quartz Sand: Quartz sand filler for arc extinguishing (Source: LSP); Dimensions: 10×85mm standard (Source: LSP); Ceramic: Ceramic body with metal end caps (Source: LSP)—Breaking: 30kA + 50kA + Filler (Three capabilities).
V.
Specifications and Dimensions
10×38: Residential string current ≤ 30A (Source: Kuangya); 14×51: 32–63A mid-range (Source: Kuangya); 10×85: C&I high-voltage applications (Source: Kuangya); NH: Square-body NH fuses (Source: Kuangya); Base: DIN-rail mount base (Source: Kuangya)—Dimensions: 10×38 + 14×51 + NH (Three specifications).
VI. Hierarchical Coordination
String: String fuse 10–15 A (Source: Synode); Combiner: Combiner fuse 63–125 A (Source: Synode); Array: Array fuse 200–400 A (Source: Synode); Selectivity: Downstream total clearing time < Upstream (Source: Synode); Brands: Bussmann, Mersen, Littelfuse (Source: SurgePV)—Coordination: String + Combiner + Array (three levels).
VII.
Procurement Recommendations
First, verify gPV rating (IEC 60269-6); second, calculate current (1.56 × Isc); third, determine voltage (≥1.25 × Voc); fourth, check breaking capacity (≥30 kA);
fifth, select size (starting from 10×38)—Fuses: gPV + Current + Voltage (three criteria).
