DC Power System Failure; A Case Study and Implications for the Maintenance

The reliability requirements for the power supply equipment in a telephone exchange must of necessity be high, since no telephone traffic is possible if there is a break in the power supply. Most power supply equipments are known for high reliability, but this does not mean that they do not need supervision and maintenance. This paper emphasizes the importance of preventive maintenance and gives examples of the possible consequences of omissions in this respect. It also describes how the maintenance can be organized, as well as required knowledge and routines.