The advantages of a two year wet ageing test to the service performance of the medium voltage grid

Cables form an important part of the electrical power transmission and distribution networks as they carry power to areas that are not accessible by overhead lines. In addition, cables bring increased levels of reliability (lower fault rates) and lower maintenance burden. Traditionally the cost of underground cable solutions has been considered to be significantly higher than overhead solutions. However, calculations completed as long ago as 1995 show that this depends upon the basis of the calculation. The costs of cables and overhead lines are much closer when true lifetime costs (low fault rates and low losses) are included (Table 1).