AC Power Plant Modernisation in British Telecom

British Telecom has installed some 4,500 Standby Diesel Generator Sets in its telephone exchanges, radio, and repeater stations over the past 25 years. Given the changing pattern of equipment technology from analogue to digital systems, particularly in major centres, and the increasing penetration of AC operated computer based plant, a review has been completed of the power systems needed now and in the future. A study has also been undertaken of AC power and total system reliability. This paper outlines the areas of investigation and shows how enhanced plant reliability targets are being achieved, and maintenance problems reduced.