Section 7(4) in Tamil Nadu Electricity Grid Code, 2005
(4)Demand Control: Demand control is concerned with the provisions to be made by SLDC to ensure the reduction of demand in the event of insufficient generating capacity, and transfers from external interconnections being not available to meet demand, or in the event of breakdown or operating problems (such as frequency, voltage levels or thermal overloads) on any part of the Grid.Towards this end the following requirements shall be complied with:(i)Power drawing entities shall endeavor to restrict their net drawal from the Grid to within their respective drawal schedules whenever the system frequency is below 49.5 Hz. When the frequency falls below 49.0 Hz., requisite load shedding (manual) shall be carried out to curtail the over drawal. Such load shedding shall be pre-planned for each level of under frequency.(ii)Further, in case of certain contingencies and / or threat to system security, the SLDC may direct the SSLDCs and other sub stations to decrease its drawal by a certain quantum. Such directions shall immediately be acted upon.(iii)Each distribution licensee shall make arrangements that will enable manual demand disconnection to take place, as instructed by the SLDC /SSLDC, under normal and / or contingent conditions. The measures taken to reduce the entities' drawal from the Grid shall not be withdrawn as long as the frequency / voltage remains at a low level, unless specifically permitted by the SLDC / SSLDC.
