Fault-loop Impedance Test

6. Fault-loop Impedance Test

This test is carried out to confirm the fault-loop impedance value of each circuit will be low enough to ensure the operation of the protective device during a fault.

Test Equipment
To perform the fault-loop impedance test, a fault-loop impedance meter is required.

Test Procedure
• Energise all circuits
• Using the fault-loop impedance meter, proceed to the equipment to be tested and measure the earth-loop impedance at this point. Repeat for other items on the circuit.
• The measured value must be less than the maximum values as tabulated at Table B4.1 of the Wiring Rules.
• If an RCD operates during the test, the test result can be considered satisfactory.

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