KNL5-63 Residual Current Circuit Breaker(without over-current protection) It is applicable to industrial sites, commercial sites, tall buildings, and civil houses. When there is human electricity shock or if the leakage current of the line exceeds the prescribed value, it will cut off the power rapidly to protect human safety and prevent the accident due to the current leakage. lt can be used as an infrequent changeover of the line in a normal situation. lt complies with the standard of IEC/EN61008.1.