... been a score of references and textbooks on the sub,jrct as well as product standards such as IEC, IEEE, ANSI and NEMA. ISO, BS and IS and other national and international publications. ... Dabholkar and lndrajit Jadhav, ABB, Vadodara; Sanjiv Bahl, ABB, Delhi; Pankaj Sachdeva and Balamourougan, Alstom (India), Chennai; V. Mohan, Rajiv Tandon, Prem Kumar and Chand Chadha, Larsen and ... useful part for all those handling HV and EHV power systems and their surge and overvoltage protection. The part deals with the BIL of a system, protective margins and insulation coordination....