Despite of the high reliability of power transformers, in view of the serious consequences of failures, it is important that an effective condition assessment system as condition based maintenance under smart grid operations is vitally important so that faults can be detected at an early stage in order to improve the prospects for repairs and minimize the impact of any failures, under more optimization of operations. As a result, the operations of power transformer would be powering our society towards a sustainable future and the excellent performance of total condition based management under smart grid operations would also be challenging the extensive opportunities of modern power system with promising beneficial results. CLP has world class supply reliability of 99.999% which an effective condition monitoring and assessment of power transformers is an important contribution factor.