Introduction of primary and secondary leakage protection system
First-level leakage protection system
When the leakage protector acts as a In hierarchical protection, the selectivity of upper and lower actions should be satisfied. Generally, the rated leakage current of the upper-level leakage protector should not be less than the rated leakage current of the next-level leakage protector, or twice the normal leakage current of the protected line equipment.
Second-level leakage protection system
Second-level leakage protection system means that the power system should at least be equipped with leakage protection of the main distribution box and leakage protection of the switch box For secondary protection, the rated leakage action current and rated leakage action time of the secondary leakage protectors in the main distribution box and switch box should be reasonably matched to form graded and segmented protection; the leakage protector should be installed in the main distribution box and switch box. The side close to the load, that is, the power line first passes through the knife power switch, and then to the leakage protector, and cannot be installed in reverse; the leakage protector should meet the following requirements: the rated leakage operating current of the leakage protector in the switch box is ≤30mA, and the rated The leakage action time is less than or equal to 0.1s, the rated leakage action current of the leakage protector used in wet places is less than or equal to 15mA, and the rated leakage action time is less than or equal to 0.1s; the rated leakage action current of the leakage protector in the main distribution box should be greater than 30mA, and the rated leakage action The time should be greater than 0.1s, but the product of the rated leakage action current and the rated leakage action time should not be greater than 30mA.s; the leakage protector should be sensitive to action, and there should be no phenomenon of inaction or malfunction.
