Overcurrent relays coordination for commercial building

This paper presents an overcurrent relays coordination study for an 11 kV commercial building in southern Malaysia. Nevertheless, the actual study that covers the overcurrent relays, earth fault relays and earth leakage relays were executed by providing optimum and functionable relay settings prior to commissioning of the building. The calculated settings and proposed adjustment settings have been verified and simulated by ETAP power tool for predictive sequence and tripping time delay during fault. Based on the proven proposed settings, the coordination study been accepted by the concerned authority body and suggested for implementation accordingly.