scope:

This part of IEC 62561 specifies the requirements and tests for isolating spark gaps (ISG) for lightning protection systems. ISGs can be used to indirectly bond a lightning protection system to other nearby metalwork where a direct bond is not permissible for functional reasons. Typical applications include the connection to: - earth termination systems of power installations; - earth termination systems of telecommunication systems; - auxiliary earth electrodes of voltage-operated, earth fault circuit breakers; - rail earth electrode of AC and DC railways; - measuring earth electrodes for laboratories; - installations with cathodic protection and stray current systems; - service entry masts for low-voltage overhead cables; - bypassing insulated flanges and insulated couplings of pipelines. This standard does not cover applications where follow currents occur.