Section 6(16) in Tamil Nadu Electricity Grid Code, 2005
(16)Disturbance Recorders and Event Loggers: Every generating station connected to the Grid at 230 kV or above, 230 kV sub-stations with transformation capacity more than 200 MVA, all substations of voltage 400 kV and above shall be provided with disturbance recorders and event loggers and shall be synchronized with a common time reference of Global Position Satellite (GPS) System.
