@thesis{thesis, author={Ispranyoto Edy and Tambun Ra Crystal S. P.}, title ={KOORDINASI RELE ARUS LEBIH DAN RELE ARUS GANGGUAN TANAH ANTARA INCOMING DAN OUTGOING TRANSFORMATOR 150/20 KV 60 MVA GIS KARET BARU}, year={2018}, url={http://156.67.221.169/677/}, abstract={Operation of power transformer at a substation is never separated from interference, both short circuit on phase-phase or phase-neutral; same thing is also happening in Karet Baru GIS. Disruptions that occur can cause losses on the part of consumers of electrical energy, more over Karet Baru GIS is one of the suppliers for VIP consumers. Therefore, it is necessary to coordinate protection instrument on the outgoing dan incoming of transformer so that interference can be minimized as small as possible. Over current relay is preffered to be used to detect short-circuit between two phases; and ground fault relay is preffered to be used to detect short circuit a phase and neutral. The short circuit current which is happened over the current setting, on over current relay the current setting for outgoing is 2,25 Ampere and for incoming is 4,503 Ampere while in the ground fault relay the current setting for outgoing is 0,41 Ampere and for incoming is 0,205 Ampere triggers the over current relay and ground fault relay which works with the applied time setting so these can avoid the risk of damage to the electrical system.} }