Leakage electrical appliances have two types: thermal magnetic type and electronic type. Compared with electrical leakage type electrical devices, they have the advantages of small size, high precision and high sensitivity, but their anti-interference ability is poor. At present, the electronic leakage protector occupies the mainstream. When the leakage current reaches the setting value, the execution circuit receives the induced voltage signal of the secondary side of the zero-sequence current transformer and drives the conversion contact to output the leakage protection signal, so that the tripping operation cuts off the power supply.
The setting of the general terminal switch tripping current is 30mA, and the setting of the upper branch switch is 300mA. Arcing short circuit with high risk of fire is difficult to be effectively cut off by the short circuit protection, and the leakage device can reliably break the ground fault to prevent the occurrence of personal electric shock and short circuit fault.