Fault approach watchdog demarcation load switch FZW28-12/FFK/VPS5-12/NKFZW28

看门狗分界负荷开关FZW28-12/FFK/VPS5-12/NKFZW28的故障处理方式

Fault approach watchdog demarcation circuit breaker ZW20BF-12/ZW20AF-12/ZW20A-12/NKZW20

看门狗分界断路器ZW20BF-12/ZW20AF-12/ZW20A-12/NKZW20的故障处理方式 

 Column demarcation circuit breaker single-phase grounding fault action principle

8.1.1 neutral point ungrounded or neutral point earthing via arc suppression coil circuit system is normal, outlet of substation demarcation circuit breaker switch is in the closing state, once the user in the single-phase grounding fault happens, the zero sequence current near zero sequence transformer detection built-in demarcation circuit breaker to the whole network of the zero sequence current, over parameters fixed, through delay, judgment is in permanent single phase to ground fault, automatic gate demarcation circuit breaker fault zone, will be separated from the. The use of mobile phone short message communication, will report the accident information. Single user and other adjacent main line grounding fault is out of bounds of zero sequence current of the circuit breaker fault, zero sequence current transformer detected is much smaller than the setting value, the circuit breaker does not move. The single-phase grounding fault and processing as shown in figure 10.

8.1.2 low resistance grounding system in low resistance grounding system, substation though zero sequence protection, but as long as the single-phase grounding fault occurred in the user, the user demarcation circuit breaker and transformer substation protection depends on the action time coordination, demarcation circuit breaker first in substation switching action, thus cutting off the the single-phase grounding fault. Ensure electricity by other user security.

In, judgment and the grounding fault of single phase out of bounds, see Figure 10

柱上分界断路器单相接地故障动作原理
8.1.1 中性点不接地或中性点经消弧线圈接地系统线路正常时，变电站出线开关的分界断路器均处于合闸状态，一旦用户界内发生单相接地故障，分界断路器内置的零序互感器检测到的零序电流接近于全网的零序电流，超过事先整定的参数，经延时，判断为界内永久性单相接地故障，分界断路器自动分闸，将故障区隔离开。使用手机短信息通信的，还会上报事故信息。其它相邻用户和主线路的单相接地故障则属于界外故障，该断路器零序电流互感器检测到的零序电流远小于整定值，断路器不动作。单相接地故障的和处理如图10所示。
8.1.2 中性点经小电阻接地系统在中性点经小电阻接地系统中，变电站虽有零序保护，但只要是该用户界内发生单相接地故障，该用户的分界断路器与变电站保护依靠动作时限配合，分界断路器先于变电站开关动作，从而切断了单相接地故障。保证其它用户安全用电。
界内，界外单相接地故障判定和处理，见图10