IEC 61892 recognised Isolated system (IT system) as one of the neutral earthing methods. The reason being quoted from the standard as below:-
"Although not intentionally connected to earth, the so called "unearthed" or "isolated" system is in fact
capacitively earthed by the distributed...
Hi Waross,
Are you referring the current flow in the generator? The fault current has to flow from the source to the fault. Thats what we think and it seems to agree with some of the technical document from I-Gard.
Hi David,
I think the handwriting in my sketch is giving the misunderstanding. It shouuld be ZCT (Zero Sequence CT) not 2 CT.
We have calculated the capacitive charging current of each 11KV switchboard to be around 9A. To cater for failure of one NGT when two switchboards are parallelled, we...
I tried to post this question in another thread but did not receive any response. So I am starting a new thread for this.
We have three 11KV Switchboards interconnected together by bus tie breakers. Each 11KV Switchboard is earthed through a grounding transformer. The transformer is wye...
Just to side track a bit. What will be the protection scheme for Y/Broken Delta scheme? Currently, we have an 11KV system with two generators infeed (Wye connection with neutral floating). The 11KV bus is earthed through the Y/Broken delta transformer. The 11KV wye connection is earthed and the...
