rumahhutan
Electrical
Hi all,
In my system, there is no neutral point. Therefore, when a ground fault occurs, the current is very small. As a result, I cannot set the 51N relay in ETAP because the value cannot be read. Therefore, I only use the 67Ns relay as the protection system. My question is, can I use the cable line discharging value to set the relay (manual calculation)? If so, how do I do it? In some papers I've read, I've found that the basic setting for the 67N relay is the same as the 50/51 relay, only with the difference in direction. If they are the same, is it correct that the setting is between 10%-50% of the cable line discharging current value? Or is there a specific standard for determining the pickup current value of the 67Ns relay and the ZCT rating that I should use?
Thanks in advance![[glasses]](/data/assets/smilies/glasses.gif "[glasses] [glasses]")
.
In my system, there is no neutral point. Therefore, when a ground fault occurs, the current is very small. As a result, I cannot set the 51N relay in ETAP because the value cannot be read. Therefore, I only use the 67Ns relay as the protection system. My question is, can I use the cable line discharging value to set the relay (manual calculation)? If so, how do I do it? In some papers I've read, I've found that the basic setting for the 67N relay is the same as the 50/51 relay, only with the difference in direction. If they are the same, is it correct that the setting is between 10%-50% of the cable line discharging current value? Or is there a specific standard for determining the pickup current value of the 67Ns relay and the ZCT rating that I should use?
Thanks in advance
.