Revised Standards Provide Design Options for Primary and Secondary Protection
Telecommunications networks are subject to surges from lightning or power line faults, and the effects of these can be extremely detrimental to systems and equipment. The equipment in a telecommunications network needs to be protected from fault voltages and currents induced onto the conductors. Standards provide equipment test requirements guidelines and often are separated into two main classifications: primary and secondary. Standards such as ITU-T and Telcordia GR-1089-CORE, Issue 6, contain tests in which equipment is tested with the primary protector in place. With vast differences distinguishing one telecommunication network from the next, standards provide a basis for equipment suppliers and customers alike to select the surge
protection criteria that best suits their specific network application. The Alliance for Telecommunications Industry Solutions (ATIS) recently has updated its coordination document “Electrical Coordination of Primary and Secondary Surge Protection for Use in Telecommunications” (ATIS-0600338.2010) to aid in suitable design.
This paper discusses how to ensure system coordination by designing with various series coordination elements as presented in the updated ATIS document. Various system coordination styles and protection technology options will be presented with an emphasis on current-type coordination.