Analysis on Selection and Installation of Residual Current Operated Protective Device

Residual current operated protective device can provide reliable guarantee for equipment operation and users’ safety, but there are some problems in communication and practice, such as inaccurate use of terms, installation and irregular usage. This paper lists and compares the meanings and differences of terms such as residual current, earth leakage current, leakage current and zero sequence current, points out the common errors existing in the process of installation of the device, analyzes the problems that may lead to mal-operation and rejection, and provides the correct connection mode.