Direct buried is the most common and widely used installation method for underground power cable system. However, the installation characteristics that have been used in recent times do not have an optimum level of cable ampacity which could not support the increasing demand of electrical energy utilization. Besides, the existing installation characteristics have deteriorated the operational lifetime of the cables and in many cases have led to cable failure. Therefore, this projects aims to optimize the installation characteristics for underground cable system. The new optimized installation characteristics will ensure that the 11kV underground cable system is able to transmit electricity with an optimum cable ampacity. Throughout this project, CYMCAP software have been used to model and simulate the installation configuration based on the entered parameters in order to calculate the cable ampacity. The objective of this project have been achieved by recommending two new installation characteristics for the 11kV underground cable that can deliver an optimum cable ampacity. The two new optimized installation characteristics are firstly in changing the insulation material and secondly in changing the backfilling material. Hence, by using these two new optimized installation characteristics, the 11kV underground cable will be able to transmit electricity at higher ampacity and also increase the operational lifetime of the power cable whilst minimizing the occurrence of cable fault.