Design and Engineering

Extra High Voltage power cable systems are usually designed based upon a standard set of input values, of which ground thermal resistivity is an input value i.e. typically 1.2 TR (Km/W) for a summer rating and 1.05 TR (Km/W) for a winter rating.

Significant savings, in certain circumstances, could be made in terms of reduced conductor size, volumes of backfill aggregate etc. If it was found that the actual ground thermal resistivity along the cable route was significantly lower than the design values used.

Experience has shown that typical readings in the right conditions can be in the order of 0.8 TR (Km/W).

VolkerInfra has the necessary resources to undertake on-site thermal resistivity testing using our Digitron D6 TR Tester equipment and to compile reports on which power cable systems can be designed.

VolkerInfra provides field testing services to measure the thermal resistivity of soils or backfill materials, required for underground power cable routes built on years of knowledge and technical expertise.

Understanding the thermal behaviour of soil is part of any cable design and will allow determination of the variations and characteristics of thermal dissipation that exist in the soil.

This information helps to determine the optimum cabling requirements, cable alignments and to identify the most suitable cable backfill material.

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