KS C4613 shows high sensitivity (15, 30mA ), mid sensitivity(100, 200, 500, 1000mA), low
sensitivity(3, 5, 10, 20A). mid sensitivity is used to protect against fire by electric leakage,
200, 500mA for main circuit, speed type of 100,200,500mA for branch circuit.
High sensitivity high speed type should be used to prevent electric shocks caused by
Accordingly, KS regulation stipulates to apply ELCB, able to operate within rated
sensitivity current 30mA and 0.03s, for
prevention of electric short by leakage.
However, in case high sensitivity is not able to be applied because of continuous leakage
current or rush current,
according to Korean electricity equipment regulation, sensitivity current as a contact
voltage human safety in ELCB is stipulated.
In this case, by controlling protection earth resistance and lowering flow current in the
electric shock is prevented.