Testing equipment, testing methods and storage

Abstract

The design refers to the following equipment: a leakage current detector 11 configured to detect leakage current flowing through a star-connected conductor; a voltage detector 12 configured to detect voltage; a phase angle detector 13 configured to detect phase angle based on leakage current and voltage; and a first determiner 14 configured to determine which angle range the detected phase angle in the previous measurement belongs to. The second detector 15 is configured to determine the phase angle detected in the current measurement based on the angle range it falls within; and the calculator 16 is configured to calculate at least the difference between the resistive component leakage current detected in the previous measurement based on the results determined by the first detector 14 and the resistive component leakage current detected in the current measurement based on the results determined by the second detector 15.