One of the several features characterizing smart grids is the different technologies of the connected Distributed Generation (DG) and the multi looped structure of Distributed Network (DN). The continual increase in the share of DG significantly influences the topology and dynamics of DNs and fault current levels. The high level of fault currents may cause hazards in terms of heat and pressure associated with the Arc Flash Incident Energy (AFIE). This paper addresses the seriousness of the AF in accordance with the optimal coordination of OCRs in DN. A new characteristic is formulated for the coordination problem of OCR scheme combining AF assessments according to constraint variables. Water Cycle Algorithm (WCA) approach is adopted to obtain the aforementioned purpose. The performance of the proposed approach is verified by using the part of IEC Mircorgrid Benchmark. The effectiveness of the proposed approach is verified by comparing the results with the traditional approach of coordinating OCR scheme.