Dalam pengoperasian generator pada suatu pembangkit tenaga listrik tidak pernah lepas dari gangguan, baik gangguan hubung singkat fasa-fasa maupun fasa ke tanah, sama halnya yang terjadi pada pembangkit PT. Puncakjaya Power. Gangguan yang terjadi dapat menimbulkan kerugian di pihak konsumen energi listrik terlebih lagi PT. Puncakjaya Power karena merupakan salah satu penyuplai bagi konsumen VIP. Relay differensial digunakan untuk mendeteksi hubungan singkat antar fasa dan mendeteksi hubungan singkat fasa ke tanah. Arus gangguan hubung singkat yang melebihi setting arus memicu relay differensial bekerja sehingga dapat menghindari resiko kerusakan pada sistem kelistrikan. Sehingga dalam relay differensial ditentukan minimum setting sebesar 32,35% untuk meningkatkan kepekaan terhadap arus gangguan dipilih minimun setting sebesar 35% dengan error missmatch sebesar 3%.

In the operation of the generator at a power plant is never separated from interference, both the short circuit phase and phase interference to the ground, as well as what happens to the generator PT. Puncakjaya Power. Disturbances that occur can cause losses on the part of consumers of electrical energy especially PT. Puncakjaya Power because it is one of the suppliers for VIP consumers. Differential relays are used to detect short-circuit between phases and detect phase short-circuit to ground. The short circuit current that exceeds the current setting triggers the differential relay to work so as to avoid the risk of damage to the electrical system. So that in a differential relay is determined a minimum setting of 32.35% to increase sensitivity to the fault current, the minimum setting is 35% with a missmatch error of 3%.