石化企业低压成套设备应注意的相关问题

Several Relevant Problems of Low Voltage Set Equipment in Petrochemical Enterprises

针对石化企业低压供电系统TN-C-S接地制式,指出低压成套设备Ⅰ段、Ⅱ段进线开关和母联开关应选用四级断路器,N线随三相相线同时关合与分断,保证供电系统在正常和异常运行方式下都符合TN-C-S要求;单相短路时应快速切除该相故障,而不应关闭主断路器的单相接地保护功能;630 kVA以上大容量变压器接地保护零序CT应安装在变压器上,而不是在进线开关柜里。该建议有利于优化石化企业低压成套设备的配置。

Aiming at the TN-C-S grounding in low voltage power supply system of pertrochemical enterprises,that the low voltage set equipmentⅠ,Ⅱsection input line switch and bus coupler switch should choose 4-pole circuit breaker,and N line should make or break simultaneously with 3-phase line,which ensured the system applied with TN-C-S whether in normal or abnormal operation;when single-phase line encountered short-circuit,it should be quickly cut off,instead of disabling the single-phase to grounding protection of ...