EEI – Calculating the Critical Earth Zone
In order to protect the public telecommunications network and its maintenance personnel from overvoltages in the event of an electrical fault, a zone within sites where overvoltages can represent a potential hazard (> 650 V) is defined . This geographical zone is known as the “critical earth zone”, and a geographical position on the perimeter of this zone is the “critical earth point”. The geographical location of the public telecommunications network termination point must not be located inside the critical zone, i.e. it must be at least at the critical earth point.
EEI has conducted critical earth zone calculations for various customers using the following methodology:
- collecting the input data,
- applying the input data to Dr. FEIST’s method, or to electrical computing software,
- calculating the critical earth zone.