Rainfall in South Africa is generally divided into two seasons namely 1) winter rainfall in the western and south west part of the country and 2) summer rainfall in the central, northern and eastern regions. Rainfall in the southern part of the country is distributed throughout the year (Jandrell , et al, 2009) Summer rainfall in South Africa is generally associated with summer thunderstorms and lightning i.e. convectional rainfall (Jandrell, et al, 2009). The lightning incidence is very low for the winter rainfall region, which is characterised by frontal activity, and in the all-year rainfall region in the south. Lightning, therefore has a seasonal pattern of occurrence, primarily occurring during summer. Eskom previously operated a LPATS (Lightning Position and Tracking System) system to detect lightning. Since 2006 this has been replaced by FALLS (Fault Analysis and Lightning Location System) operated by the South African Weather Services due to the previous system reaching the end of its life and not meeting operational requirements (Evert & Schulze , 2005). Fire Air normally acts as an isolation medium between live conductors and the ground due to its di-electric properties. During a fire the properties of air change due to smoke and particles that occur between the lines and the ground, possibly resulting in a flashover. Three theoretical models have been proposed to explain the reasons for this and these relate to 1) reduced air density, 2) presence of conductive particles in the air and 3) conductivity of the flames (Sukhnandan & Hoch, 2002). Faults are commonly caused by veld and sugar cane fires under lines and line
Rainfall in South Africa is generally divided into two seasons namely 1) winter rainfall in the western and south west part of the country and 2) summer rainfall in the central, northern and eastern regions. Rainfall in the southern part of the country is distributed throughout the year (Jandrell , et al, 2009) Summer rainfall in South Africa is generally associated with summer thunderstorms and lightning i.e. convectional rainfall (Jandrell, et al, 2009). The lightning incidence is very low for the winter rainfall region, which is characterised by frontal activity, and in the all-year rainfall region in the south. Lightning, therefore has a seasonal pattern of occurrence, primarily occurring during summer. Eskom previously operated a LPATS (Lightning Position and Tracking System) system to detect lightning. Since 2006 this has been replaced by FALLS (Fault Analysis and Lightning Location System) operated by the South African Weather Services due to the previous system reaching the end of its life and not meeting operational requirements (Evert & Schulze , 2005). Fire Air normally acts as an isolation medium between live conductors and the ground due to its di-electric properties. During a fire the properties of air change due to smoke and particles that occur between the lines and the ground, possibly resulting in a flashover. Three theoretical models have been proposed to explain the reasons for this and these relate to 1) reduced air density, 2) presence of conductive particles in the air and 3) conductivity of the flames (Sukhnandan & Hoch, 2002). Faults are commonly caused by veld and sugar cane fires under lines and line
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