TCN’s General Manager, Mrs Ndidi Mbah, made this known in a statement in Abuja on Thursday.
It would be recalled that there was national grid collapse at about 11.01am Wednesday.
TCN said that the total system collapse of the grid was as a result of voltage collapse in some parts of the grid.
Mbah said that the Kainji – Birnin Kebbi line, however, tripped on fault but was restored.
She said that the TCNs 330kV substations feed 132kV substations, through which Distribution Companies offtake electricity they deliver to electricity consumers nationwide.