Grounding HV/LV

[bojleric]

Hi everyone,

I'm interested in your practice concerning the ground resistance measurement’s of HV/LV (for example 20/0,4 kV)substations. Particularly if some of you work for a distribution company. Of course all the requirements and regularities come from HD 637 S1. Do you measure the resistance if the substation is connected to global earthing system of a 110/20 kV station through the earthing conductors, cable sheaths and other underground metallic utilities. How do you measure it? Using conventional ground resistance testers (3 pole / 4 pole measurement)? How do you measure substations that are not connected to the global earthing systems, the ones that have a HV overhead connection lines? Do you use U-I method described in HD 637 S1. I think that when measuring substations you can’t use conventional ground resistance testers because in most substations you have joined HV and LV earthing system which means that the PEN conductor in the LV is also a part of the earthing system. What are your experiences?

 

[dpc]

Of course all the requirements and regularities come from HD 637 S1

Of course that might depend somewhat on the reader's location. What country or region are you interested in?

 

[bojleric]

Europe...