GB 50054-2011 第6.4.1条
| **** | The short-circuit protection device for distribution circuits shall be capable of breaking the circuit before the short-circuit current raises the conductor to the permissible limit temperature. For cables or insulated conductors in hotels, the short-circuit duration shall not exceed 5 s (for PVC-insulated conductors) or 0.4 s (for XLPE-insulated conductors), calculated specifically according to the thermal stability verification formula \( S \geq \frac{I \sqrt{t}}{k} \), where S is the conductor cross-section (mm²), I is the RMS short-circuit current (A), t is the short-circuit duration (s), and k is the conductor coefficient (115 for copper-core PVC insulation, 143 for XLPE). |