@thesis{thesis, author={Irwansyah Putra and Pahiyanti Novi Gusti}, title ={Studi Pengaruh Pembebanan Dan Suhu Terhadap Susut Umur Transformator Tenaga 60 MVA Di Gardu Induk Gandul 150/20 kV Unit 3}, year={2018}, url={http://156.67.221.169/1158/}, abstract={In the medium voltage distribution network is one of the electric power systems that cannot be avoided. This can cause damage to electrical equipment so that the continuity of a distribution system is disrupted. To overcome this, an effective protection system is required to have several conditions, namely fast, selective and reliable so as to reduce the impact of the disturbance. In the 20kV distribution network in the orange garden substation, most use medium voltage cable lines (SKTM). In determining the reliability of electric power supply systems is to install protection system equipment on the distribution network that is handled with special integrity. Based on the PMT trip analyst in the johar feeder and the incoming side the type of interruption is the moment, the relay at the feeder and the incoming trip side. This is due to the relay on the johar feeder and the incoming side which is not optimal, by setting the overcurrent relay and ground fault relay on penyulang johar and on the incoming side then the relay work curve in the feeder feeder is earlier than the incoming side. So that it is expected that the relay performance can be optimally worked on johar feeders.} }