Residual current sensor principle

- Nov 04, 2019-

Residual current sensor are often used in conjunction with residual current electrical fire monitoring detectors for the detection of leakage currents (ie residual current), which is a special type of transformer consisting of a coil and an iron core. The principle is based on Kirchhoff's current law: the algebraic sum of the complex currents flowing into any node in the circuit is equal to zero. When the line and electrical equipment are normal, the vector sum of each phase current is equal to zero, and the secondary side winding of the residual current sensor has no signal output; when the ground fault occurs, the vector sum of each phase current is not zero, and the fault current makes The magnetic flux is generated in the toroidal core of the residual current and current transformer, and the secondary winding generates a signal. When the electrical fire monitoring detector receives the signal, an alarm is issued.