“Stray current” is a real danger.
https://www.youtube.com/watch?v=Yg6G5VUSsWA
Ground resistance testing is a crucial aspect of electrical safety and compliance with electrical codes. The process involves measuring the resistance of the grounding system to ensure that it meets the required standards for electrical safety.
In a real-world experiment with electrical code expert Mike Holt, ground resistance testing may involve the following steps:
1. Selection of Testing Equipment: Holt may begin by selecting the appropriate ground resistance testing equipment for the specific application. This typically includes a ground resistance tester or a clamp-on ground resistance tester, as well as test leads and auxiliary equipment such as grounding stakes or rods.
2. Preparation of the Test Site: Holt would then prepare the test site by ensuring that the area around the grounding system is clear and accessible. Any surface debris or vegetation that could interfere with the test should be removed, and the grounding electrodes should be exposed for testing.
3. Connection of Test Equipment: Holt would connect the ground resistance tester to the grounding electrodes using test leads or clamps. The tester would be configured according to the manufacturer’s instructions, including the selection of the appropriate test method (e.g., three-point or four-point testing).
4. Execution of the Test: With the test equipment properly connected, Holt would execute the ground resistance test by applying a test current to the grounding system and measuring the voltage drop across the electrodes. The tester would calculate the resistance of the grounding system based on Ohm’s Law (R = V/I), where R is the resistance, V is the voltage drop, and I is the test current.
5. Interpretation of Results: Based on the measurements obtained during the test, Holt would interpret the results to determine whether the ground resistance meets the requirements specified by the applicable electrical codes and standards. This may involve comparing the measured resistance to the maximum allowable resistance specified in the code or conducting additional tests to verify the integrity of the grounding system.
6. Documentation and Reporting: Finally, Holt would document the results of the ground resistance test and prepare a report detailing the findings. This report would typically include information about the test methodology, equipment used, measured resistance values, and any recommendations for corrective action if the grounding system fails to meet the required standards.
Overall, ground resistance testing with an electrical code expert like Mike Holt is an essential process for ensuring the safety and reliability of electrical systems, and it helps to verify compliance with electrical codes and standards.