I have difficulties to get a way how to make a good coordination in over current relay. Please give me an example in a real condition to make a good coordination......
Thank you..
I you visit the Areva T&D site they have their NPAG manual on-line which will help you. You can also search for other documents (ABB, Siemens and Schneider all have guides on line which address the topic). You can also find some tutorials if you search Google.
The Wiki here also have some informations, although I guess it would do with expanding a bit.
Actually it is very difficult to answer in two lines of your query regarding relay coordination.Relay coorniation needs
1.Fault calculations at start node to end node of the distribution network to be calculated/
2.What are the loads at HT/LT bus bars at different different notes on the HT/LT bus bar.On every bus there are no of loads of different ratings?hence fault level is also different for different loads and a common fault level to be calculated at the incomer.
3.Same for LT network.
4. Also included what are the sources of supply,how many transformers are there.
if you are saying regarding that then called a consultant for this. If you have a special case then come with detail descrption to which any one can help.