On the 4th of October at 1:02 pm, a monophasic short circuit in transmission line 138 kV Samambaia - Brasilia Norte, caused by fire, was eliminated by the action of the protection of that line, resulting in automatic shutdown of various transformers and transmission lines in Distrito Federal. There was total loss of loads served by substation Brasilia Sul, in an amount of approximately 900 MW.

Main actions and measures implemented:

• Implementation of new operating procedures for the transfer of loads from Águas Claras of substation Samambaia to substation Brasilia Sul. To avoid overload of circuit 3 of 138 kV Brasília Sul - Brasília Norte, only a portion of the priority load of Águas Claras, around 15 MW, will be transferred to substation Brasilia Sul.
• Adequacy of SEP in Brasilia Norte, which now operates only on account of overload in any transmission lines at 138 kV Brasília Sul - Brasília Norte (circuits 1,2 and 3) or Samambaia - Brasilia Norte.
• Implementation of operating procedures on 138 kV grid from CEB, regarding the procedures and operating limits involving circuits 1, 2 and 3 from 138 kV TL Brasília Sul - Brasília Norte, 138 kV TL Samambaia - Brasilia Norte and substation Águas Claras at 138 kV, from CEB.
• Activation of three pole automatic restart on 138 kV Brasília Sul - Brasília Norte (circuits 1, 2 and 3) and Samambaia - Brasilia Norte.