Section 19A(1)(e) in Tamil Nadu Electricity Regulatory Commission Intra State Open Access Regulations, 2005
(e)Grid support charges(i)The distribution licensee shall raise bills on the open access customer for the drawal of power from the grid by the consumer as back up supply under the conditions specified in clause (a) of sub-regulation (7) of regulation 9, within five days from the date of meter reading.(ii)The open access customer shall pay the charges within seven days from the date of the bill.