Thank you for your question regarding LV and HV earthing at substations, it is our pleasure to help.
You may not have separate earthing systems at any location, particularly at substations. It would be very hazardous and would actually increase the problems you are having.
In your case, your substations earthing system is probably inadequate to handle the current levels it is experiencing. Fortunately in your case, a standard Step & Touch Voltage Safety Analysis will not only resolve the problems you are having with your LV equipment, but it will also make the site safe for the people working in the facility.
A Step & Touch Voltage Safety Analysis is easy to do, all you need is to provide us with site drawings, soil data and the substations electrical fault data. Via email, we can analyze your facilities earthing system using the CDEGS engineering simulation software, and provide you with recommended improvements to your earthing system that you can then implement.
Please contact us at 310-318-7151 California time and someone will be happy to speak with you about analyzing your project and making it safe for personnel and equipment.
The Engineering Team at E&S Earthing Solutions
Photo credit: E&S Earthing Solutions