In this paper, we analyzed form of flowing leakage current in electrical installation. Leakage current ($I_g$) is consisted of resistive leakage current($I_{gr}$), capacitive leakage current($I_{gc}$), and inductive leakage current($I_{gl}$). Resistive leakage current($I_{gr}$) is big occasion than capacitive leakage current($I_{gc}$) in system, Residual Current Protective Device(RCD) detects correctly leakage current. But,$I_{gc}$ is big occasion than $I_{gr}$, RCD is malfunctioned It is resistance to lead to electric fire in electrical device. We manufactured outlet that resistive leakage current detecting circuit is had. Manufactured outlet displayed performance exactly in leakage current of 5 mA Therefore, this product estimates that contribute on electric fire courtesy call.