What is Grounding Measurement and How is it Performed?
Short answer: Grounding measurement is an electrical test performed to determine whether a facility's grounding system can safely conduct fault current to the ground. The most common method is performed using a calibrated grounding measuring device (ground megger). It is the three-point (falling potential) method.. The measurement gives the grounding resistance in ohms.
Grounding is the invisible but most critical component of electrical safety. In the event of a fault, it safely conducts leakage current to the ground, protecting people from electric shock and preserving equipment from damage. However, the only proof that grounding is performing this function is regular measurement.
What tests are performed during grounding measurement?
- Grounding resistance measurement: Resistance of the grounding electrode relative to the ground (three-point method)
- Soil resistivity: Electrical resistance of the ground (Wenner four-electrode method) — used in new designs.
- Continuity measurement: Integrity of protective conductors and equipotential bonds.
- Loop impedance: The fault cycle must be low enough to trigger the protective device.
How is the measurement taken?
- The facility's grounding system and electrodes are determined.
- The calibrated grounding measuring device is installed in the field with auxiliary electrodes.
- Resistance is measured using the three-point (falling potential) method.
- Continuity and other necessary tests are performed.
- The results are compared with regulatory/standard limit values and reported.
Measurement for accurate results with calibrated devices And it must be done by authorized personnel; incorrect methods or uncalibrated equipment can incorrectly approve an installation that appears safe.
Frequently Asked Questions
Who can perform grounding measurements?
Measurements must be performed by a qualified electrical engineer/technician using calibrated equipment; a TÜRKAK accredited organization should be preferred for the report's validity.
Are soil resistivity and grounding resistivity the same?
No. Soil resistivity is a property of the soil (for design purposes); grounding resistance is the resistance of the installed system to the soil (for verification purposes).
For accredited grounding measurements. Our Grounding Systems Services Examine it.