民用建筑低压供电小议  

Simply Discussion on Low-voltage Power Supply in Civil Buildings

作　　者：胡良德[1] 

机构地区：[1]云南省设计院,昆明市650032

出　　处：《建筑电气》2007年第7期29-30,共2页Building Electricity

摘　　要：在民用建筑的低压供电系统中,对未设有10/0.4kV变电所的建筑物,低压电源由建筑物外的变电所用电缆供电,多采用TN-C-S系统。因电缆截面不同,线路电阻也不同;或不同的配电室,其等电位联结线阻抗的差异,导致各回路PEN线电流并非是本回路PEN线电流,而是按并联后的PEN线电阻及等电位联结线阻抗进行重新分配,造成PEN线电流变化且方向不定。可能对电子设备及数据产生干扰,对铠装电缆或穿金属管敷设的电缆产生涡流损耗。The building which does not establish 10 / 0.4 kV substation usually adopts TN-C-S system in the low-voltage power supply system of civil building. And low-voltage power source is provided through cables from substation out of the building. Owing to the difference of cables cross-section,the circuit resistance is also different;or in different distributing rooms,the difference of the equipotienal bonding conductor's impedance leads to the PEN conductor current of each loop not its own current,but the current of the resistance of PEN conductor paralleled and the impedance of equipotienal bonding conductor redistributed. It is easy to cause uncertain values and directions of the PEN conductor's current. Electrical equipments and data will be disturbed for this reason. And armored-cable or run-in-metal-conduit cable will produce vortex loss.

关 键 词：PEN线 TN系统 重复接地 涡流损耗 

分 类 号：TU85[建筑科学]