Leakage current protection circuit

The leakage current protection circuit is a traditional electromagnetic tripping device. It directly accepts the signal from the zero-sequence current transformer and has high sensitivity
. Generally, boron uses a polarized electromagnet and can operate when the leakage current reaches 30mA. When there is no leakage current, the permanent magnet of the leakage release will
attract the armature and it will be in normal working condition. When the protected circuit leaks to the ground, the current input from the secondary winding of the zero-sequence current transformer to the tripper coil
generates magnetic flux, which offsets the magnetic flux of the permanent magnet within half a cycle, and the armature is released by the tension of the spring. , the tripper operates and
the relay contacts are connected or disconnected within 0.1s. Adjust the spring so that there is a certain gap between the armature and the yoke, then the operating current can be adjusted.