Protection of electronic equipment in a substation environment

High-energy transients or faults cause failures in low voltage substation equipment such as solid-state relays, remote terminal units, or communication equipment. Sometimes, due to these influences, relays operate erroneously causing interruptions that were not called for. Operational problems resulting from the failed equipment also include loss of audio/video signals and data transmission. The overvoltages may even destroy the protective devices such as gas discharge tubes or metal oxide varistors. The objective of this paper is to present protection guidelines that address the above concerns and prevent the electronic equipment failures in substations. Test methodologies and data supporting these guidelines are also presented. The specific areas of focus include grounding and shielding practices for substation control and communication cables.