الفهرس 
ABSTRACT
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Abstract
Joint boxes usually act as hot spots in most of the practical underground cable systems. As the maximum permissible temperature rise for cables is limited to a value generally less then 85 C, joint boxes and the moisture content of the soil both affect the maximum current carrying capacity of the underground cables and the permissible time during overload periods. A study of the variation of the maximum permissible current and the permissible overload time according to the above two factors have been investigated here.
Due to the complexity of the problem e.g. the heating affect of the electric current may change the moisture distribution in the soil than its value at the first initial conditions, the conclusion and comments are presented here according to the experimental results which were carried out for single core cable in sand and clay soils with different moisture contents. For other cables, soils and joint boxes similar results could be deduced and the corresponding results are expectes in most practical cases to have the same family relations as those presented here.
The thesis is divided mainly in four chapters:
Chapter I- Deals with general review of previous works.
Chapter II- and chapter III - Deal with experimental work and results. Methods are given to check experimental results obtained for maximum temperature rise and time constant.
Chapter Iv- Illustrate the temperature distribution and the behaviour of maximum safe current carrying capacity of the cable with and without joint boxes.