Uploaded December 2025 | Updated September 2026, 1 week ago
In this short video, we demonstrate how to carry out a live test of external earth fault loop impedance (Ze).
To obtain an accurate Ze value, the installation must first be isolated. The earthing conductor is then temporarily disconnected from the main earthing terminal. This step is essential, as it removes any parallel earth paths that may be present due to protective bonding.
Protective bonding to incoming metal gas, water, or oil services can create additional earth paths, which may give a falsely low reading if left connected. By disconnecting the earthing conductor, we ensure the test measures the true external earth fault loop impedance supplied by the distributor.
This procedure helps confirm the integrity of the external earth and ensures compliance with inspection and testing requirements.
Videos are training aids for City and Guilds (C and G) and EAL courses Level 1, 2, 3 plus AM2, AM2S and AM2E.
You can follow me day by day on Facebook, Instagram, Twitter and TikTok lookout for "GSH Electrical.
#GSHElectrical #electricaltrainingvideos #electricalwiring #electricaltesting
In this short video, we demonstrate how to carry out a live test of external earth fault loop impedance (Ze).
To obtain an accurate Ze value, the installation must first be isolated. The earthing conductor is then temporarily disconnected from the main earthing terminal. This step is essential, as it removes any parallel earth paths that may be present due to protective bonding.
Protective bonding to incoming metal gas, water, or oil services can create additional earth paths, which may give a falsely low reading if left connected. By disconnecting the earthing conductor, we ensure the test measures the true external earth fault loop impedance supplied by the distributor.
This procedure helps confirm the integrity of the external earth and ensures compliance with inspection and testing requirements.
Videos are training aids for City and Guilds (C and G) and EAL courses Level 1, 2, 3 plus AM2, AM2S and AM2E.
You can follow me day by day on Facebook, Instagram, Twitter and TikTok lookout for "GSH Electrical.
#GSHElectrical #electricaltrainingvideos #electricalwiring #electricaltesting
