There has been a vast vacuum in the literature on the importance of the location of remote earth carried out during impulse test on grounding systems using field measurements. Some published work show that the remote earth is installed surrounding the electrode under tests, whilst some have used separate remote earth, away from it. This work studies the impact of return electrode location on transient behaviour of the earthing electrode. The electrode under test is a single rod. Two types of remote earth configurations are used, a circular electrode with multiple rods surrounding the single rod, and one that is 80m away from it. Impulse tests are conducted under both impulse polarities. Voltage and current traces are captured for a single rod, using two different types of remote earth configurations, with the impulse resistance measured as well. It has been established that the arrangement of the remote earth poses no influence on the test results. That said, higher oscillations of current traces and higher resistance values have been observed in negative impulse in comparison with positive impulse polarities.

Nowadays, with a good design and available facilities of high impulse generators that can be taken to field sites for measurements, much research work can be found on the field measurement on the study of the grounding under fast transients. Moreover, field tests on earthing systems have become interesting since it can provide the closest scenario of the characteristics of grounding system when fast transient current discharged to the earthing systems. However, the field measurements have some limitations on the standard methodologies that should be adopted during the field measurements. There is also very little being mentioned on the arrangements/values of the remote earth. As generally known, the remote/auxillary earth is important not only for the purpose of discharging any high fault current during the tests on the electrode under tests, but also to ensure that the remote earth is not being included in the measurements, hence affect the accuracy of the measurements. Due to these factors, this paper is to aimed to study how different configurations and resistance values of remote earth on the characteristics of main earthing systems. It was found that different results were obtained when higher earth resistance values of remote earth were used for impulse tests on main earthing systems.