Circuit protection for telephone networks - needs and co-ordination

Microelectronics devices installed in telecommunication equipment are growing increasingly sensitive to electrical disturbances transferred from the outside-plant cable networks. Telephone service providers are aware of the origin of these disturbances and are implementing practices on how best to avoid or combat their effects. Good grounding practices together with a co-ordinated approach to electrical protection are essential for effective protection. This paper reviews the origins of these disturbances, the grounding needs and the design criteria for co-ordinated multistage protection