Earth fault-loop impedance Calculator

*The following calculator is for reference only.

$$ Z_s=\frac{U_{\circ}}{I_a} $$
Uo , Nominal phase voltage
Circuit breaker size(A)
Select Circuit breaker type : Type B, Type C, Type D
I(rated current)*


= Ia , trip current setting for the instantaneous operation of a circuit breaker or the current that assures operation of the protective fuse concerned, in the specified time
Zs , Maximum permissible earth fault-loop impedance (Ω)