<p> A lightning strike could bring thousands mega-ampere of current in a blink of eyes. As a result, a failure of grounding the strike may cause serious damage to the home and industrial appliances and gadgets. Hence, a lightning protection system is essential to the current transmission system. Lighting is a natural phenomenon that is unavoidable. Hence, the study of the properties and characteristics of lightning is a must in designing lighting protection system. Every application has different criteria to be fulfilled. The type of lighting protection system is categorized based on the location and user. The different of location is a public area, transportation system, power system transmission and generation system which include renewable energy source. Each area can conclude different level of protection. This paper is assessing the possibility and probability of transient impact on all applications including, public area, power system line, and generating system. The review includes countermeasure which addressed few steps to determine the effect of lightning and countermeasure of protection.</p>

<p>Oils acts as insulation and cooling agent in the transformer. Petroleum-based oils are widely used in transformers due to their qualified properties as good insulation materials. Unfortunately, the used of petroleum-based oils has adverse effects on environment in the event of any failure to transformers such as tank leakage or explosions. Therefore, researchers have been studied and have found environmentally friendly oil that is suitable as substitutes in transformer. Thus, breakdown voltage tests using direct current and alternating current with the addition of different water content were performed to identify the potential of palm oil and coconut oil in the transformer isolation system. Refined, Bleached and Deodorized oil (RBDPO) and coconut oil samples were selected to be test in this study. The oil samples were test by varies the gap distance of test cell electrode and the level of water content. As a conclusion, RBDPO oil has greater breakdown voltage test under DC breakdown voltage test in term of increment of the gap distance.</p>