Cable temperature monitoring

The National Grid Company (NGC) has been installing fibre optic temperature monitoring on selected cable circuits since 1993, in an effort to gain more knowledge of the thermal behaviour of buried power cables. Three DTS-80 machines have been purchased from York Sensors, which are rotated between particular sites. Data retrieval is by modem link. On all installations so far, the fibre optic cable has been attached to the outside of the power cable. Keeping the fibre optic external to the power cable has many advantages but also a few disadvantages which are briefly outlined. The fibre optic cable is described and the benefits of the system are discussed