Over Current Relay is a device that detects the presence of overcurrent, whether caused by a short circuit fault or an overload that can damage power System equipment in its protection area. The inverse curve characteristic is very useful for securing overload / overload, because it works with a time delay that depends on the amount of current in reverse (inverse time), the greater the current the smaller the delay time however, due to limited tools, researchers created a Methode Program Inverse program so that the characteristics of the curve could be seen.
This research aims to determine the type of inverse curve characteristics using Methode Program Inverse if an overcurrent disturbance occurs in a 24kV medium voltage network System that uses an inverse curve type time delay setting on the protection Relays used. This research uses laboratory, field and quantitative analysis methods.
The results of the study include showing that the characteristics of the inverse curve viewed with Methode Program Inverse are that the tripping time of the Circuit Breaker will be in accordance with the amount of current flowing, if the fault current is small then the tripping time of the Circuit Breaker will be long, conversely if the fault current is large then the tripping time of the Circuit Breaker will be faster and the Relay coordination will run properly.
Keywords: Inverse curve, Over Current, quantitative, analysis, discussion, and conclusions