Siddhivinayak Enterprise Kolshet Road, thane, Maharashtra

It is not possible to use line current directly for measurement and relaying purpose due to its high value and insulation problem. CURRENT TRANSFORMER which is widely known as 'CT' is a piece of electrical equipment which converts line current values which are suitable for the devices to which is connected e.g. measuring instruments, meters, protection relays.

Need for checking the adequacy of Insulation, provided in the electrical apparatus, cannot be over emphasized. Insulation between the live and earth or between two different sections of live parts, this insulation is required to be tested at high voltage values recommend by applicable relevant standards. The standard specifications for various electrical apparatus specifies power frequency voltage withstand tests at different levels depending upon the working voltage of electrical apparatus. It is observed from the various standard for electrical equipments that the minimum power frequency voltage withstand test level for electrical Insulation is 2KV for one minute.