@thesis{thesis,
		author={Hajar  Ibnu and Vernanda  Dhimas Alviero Daffa},
		title ={ANALISIS PENGUJIAN TANGEN DELTA PADA TRANSFORMATOR DAYA 5 PADA GARDU INDUK SENTUL 150KV.},
		year={2021},
		url={http://156.67.221.169/3739/},
		abstract={Power transformer is a tool that serves to transform a higher voltage system to a lower system voltage for the needs of indicator equipment, measuring instruments / meters and relays. The age and time of operation result in the voltage transformer experiencing a decrease in as well as malfunction. Therefore, it is necessary to test to know the condition of the power transformator one of the testing methods used in the power transformer is delta tangent testing where this test serves to determine the decrease in isolation capability of a equipment and capacitance value of the equipment, in testing delta tangents on this transformer using delta megger 4010 tangent test tool. The factors that affect the value of delta tangent test results are temperature, dirt, humidity as well as damage to the transformer mechanism. This delta tangent test refers to an ANSI C 57.12.90 standard that says if the delta tangent value does not exceed 0.5% then the transformer is in good condition. If the delta tangent value exceeds 0.5%-0.7% then the insulation quality of the transformer decreases.}
		}