Assessing single fault immunity in an operating switching and transport system

DC power plant architectures, distribution and ground systems used for powering telecommunications equipment should be designed to meet overall system availability objectives. However, because of the myriad power system architectures, and distribution and grounding topologies used today, the performance of switching and transport systems during and after power related failures may be completely different when the same systems are installed in different locations and environments. While the majority of equipment manufacturers test their individual products for compliance with industry standards, tests of the power and telecom systems as a functioning unit are usually not performed prior to placing them in service. This paper describes and presents a test plan and specific tests that can be used to determine if overall system availability is compromised when any type of switching and transport system is installed and ready to be placed in service. These tests can uncover problems and errors associated with engineering, installation, and the customer´s and manufacturer´s intended mode of operation. The discussion that follows is intended to show the increasing complexity of these configurations, which leads to the conclusion that system testing is virtually a requirement before placing service on the telecom. equipment.