@thesis{thesis, author={Dewi Emma Agustina Tiara and Suwarno Suwarno}, title ={STUDI KOORDINASI PROTEKSI ARUS LEBIH PADA PENYULANG JAKARTA FAIR8 20 kV GARDU INDUK KEMAYORAN}, year={2017}, url={http://156.67.221.169/907/}, abstract={Electricity is a primary needs which should be economically available and regard the quality and reliability of its. To maintain the continuity of electricity require a protection system which comply the requirement. But in fact, feeder of medium voltage which stream the electricity frequently interrupted, such as short-circuit current. Therefore, to separate the interruption require the protection system which precise and reliable. The protection system is worked by considering the security of device, stability of electricity, and security of human. Jakarta Fair8 feeder is using over current relay (OCR) and ground fault relay (GFR) as protection devices, which protect medium voltage underground line system. We obtained that rating for the current setting of over current relay (OCR) is 4,76 A for outgoing transformator side and 3,369 A for incoming feeder side. And rating for the tms of over current relay (OCR) is 0,2 s for outgoing transformator side and 0,17 s for incoming feeder side. Rating for the current setting of ground fault relay (GFR) is 0,21 A for outgoing transformator side and 0,86 A for incoming feeder side. And rating for the tms of ground fault relay (GFR) is 0,28 s for outgoing transformator side and 0,19 s for incoming feeder side. With 0,4 s different coordination time.} }