GB 7588-2003 第13.5.1条
| **** | **Grounding protection**: All metal enclosures of electrical equipment, elevator guide rails, cars, conduit, etc. must be reliably grounded, with grounding resistance ≤ **4Ω** (≤1Ω is recommended for hotel buildings due to high occupant density). The neutral line and ground line shall be strictly separated (TN-S system). Grounding conductor cross-sectional area: when the phase conductor is ≤16mm², the grounding conductor shall be ≥ the phase conductor cross-sectional area; when the phase conductor is >16mm², the grounding conductor shall be ≥ **50%** of the phase conductor cross-sectional area. |