Why Is Earth Fault Loop Impedance Important. If you own a business you are legally responsible for the safety of your employees this means providing a safe environment to work in. It is important to know the earth fault-loop impedance of a circuit to ensure that during the occurence of a phase-to-earth fault normally an insulation fault the magnitude of the fault current is enough to cause the operation of the protective device within the required time particularly where the touch potential exceeds 50V ac.
The article also discusses the use of calculation as an alternative to loop impedance measurement as permitted by BS 7671. Earth fault loop impedance. If you own a business you are legally responsible for the safety of your employees this means providing a safe environment to work in.
The measurement is made with an Earth Fault Loop Impedance tester with the Main Switch in the OFF open position and with the means of earthing disconnected from the installation to avoid parallel paths.
Its like this. The objective is to make sure that the circuit is. It is a way of insuring that you have made an electrically safe ground connection having a suitably low residual resistance. The total earth fault loop impedance is measured by plugging a loop tester into a socket outlet or in some cases with an external earth probe.
