Measure the resistance of the ground loop without a stake

Normal earth resistance measurement involves disconnecting the parallel earth rods, setting up several auxiliary earth rods and using an earth tester to calculate the resistance of the earth system taps. But sometimes it’s just not possible to plant ground stakes, such as inside a building, in a cell phone booth, or on electricity pylons. How to do ?

Thanks to the stakeless test method, stakes are not required. Place a current clamp, such as the Fluke 1630, around the ground rod or wire. One half of the clamp produces a known voltage while the other half measures current. The tester automatically determines the resistance of the ground loop at this ground connection. You can also perform continuity test, leakage current measurement, and lightning protection system inspection by following the same procedure, even without breaking the circuit.

Remember: the stakeless method assumes that in systems with multiple or parallel grounds, the net resistance of all paths to the ground is extremely low compared to that of a single path (the one under test). So the net resistance of all resistors in the parallel feedback path is effectively zero. Stakeless measurement only measures the resistances of individual grounding rods in parallel with grounding systems. If the ground system is not parallel, you will need to have an open circuit or measure the resistance of the ground loops.

The Fluke 1630 measures earth resistance from 0.025 to 1500 ohms and true rms current from 0.02 to 35 A, and can measure non-invasive leakage currents from 0.2 to 1000 mA. It includes high/low alarm function that helps users quickly compare the measured value with the upper and lower limits, display lock function, logging function that can memorize the measured values, and automatic self-calibration.