ORDER

(Date of Hearing: 21.3.2002)

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Sustained low frequency operation or permitting the frequency variation in a wide range causes damage to the electrical equipment of power plants as well as that of the consumers. In power plants, such operation may cause damage not only to the auxiliary equipment like motors and pumps but also to turbines and generators. Last stage blades of the turbine are particularly susceptible to damage due to sustained low frequency operations. It is because of this reason that manufacturers do not recommend operation for turbo-generators at frequency beyond the standard frequency. Several cases of damage to turbines have been reported in the country due to sustained low frequency operation. We were told that a large number of the generating units, particularly the old ones might develop problems within a short duration thereby pushing the region to the unmanageable level. A wide cross-section of society from domestic and commercial consumers to farmers and industrial consumers use electricity for operating a variety of electrical and electronic equipments. These equipments are also liable to damage on account of variation in frequency/voltage of electric