Escape the normal leakage current of the grid in case selection should be selected small

Residual current operated protective devices escaped grid current value in the case of normal leakage current selection should be selected small to accommodate personal and equipment safety requirements. A final protective action current value of the setting the final stage  power transformers  protection device rated operating current is based on the shock caused by ventricular fibrillation current limit  Electric transformer  to prevent electric shock, personal direct contact with the main purpose, according to the "rural low voltage power technical regulations" requirements for household appliances, fixed installation electrical appliances, mobile appliances and temporary power equipment, the rated residual operating current is 30mA; handheld electric appliance of its action is 10mA;