Hi Dears,
I supposed that at first post above, I took screenshot from Etap page. I do not how to calculate ''Impedance OHM'' blanks. I supposed it should be zero sequence impedance. Because the only current is going to pass from grounding transformer is zero sequence current. Therefore I...
Hi;
I am trying to enter related information to zigzag grounding transformer on ETAP. Our transformer information are below. BUT, when I enter 18,2 ohm/phase to Impedance OHM subtitles, phase to ground current is limit to much. As much as I read, zero sequence of zigzag transformer should be...
Hi;
Thanks again for your reply.
Please also let you explain about below Etap screenshot. PS: I am trying to limit grounding current around 1kA and I will use zigzag transformer. Should I add also, neutral resistor for this application ? If it is possible could you explain me how can I...
Hi Guys,
Thank you very much for your reply.
Actually, at the beginning of project this site has 20MVA generator (Yn) and 20MVA (YND) step up transformer which is produce electricity for the grid. Then customer informed us, he will shutdown his generator and he will use this transformer just...
Hi Everyone;
I have two question about arc flash analysis;
1- I am doing arc flash analysis for one of our customer. I would like to learn how can we assume short circuit capacity of low voltage switchboard. There is no information on the related project and those switchboard are really old...
Hi Everyone,
I have isolated system which has 154kv/10.5kv YN/D transformer. I have to do protection for delta side of this system. In case of earth fault, I know that I can not protect my system with current. I should use 59N protection. In case of earth fault in any bus in our system...
