500kV Line Switching

Before 500kV work commence, the line should be safe from electric danger.

When we do electric switch should be involve two persons or more even more on night shift.



When open the line, CB is the first open, then open DS and the last is close ES.
When close the line, ES is the first open, then close DS and then close CB.

The 500 kB CB have three selector.
1. Local is apply from 500kV room.
2. Remote is apply from Power Station Central Control Room.
3. Supervisory is apply direct from Dispatcher.

This Example switching as follow below

Shut Down OHTL-1
1.Put selector 7 B1 and 7 AB-1 to S/V (supervisory).
2.Open CB 7B1 (from JCC)
3.Open CB 7AB-1 (from JCC)
4.Shut Down OHTL 1
5.Open DS 7B1-1
6.Open DS 7AB1-2
7.Open DS 7B1-3
8.Close ES 2TJ1E
9.Confirm Close ES OHTL 1

Restoration OHTL-1
1.Close DS 7B1-1
2.Close DS 7AB1-2
3.Close CB 7B1
4.Close CB 7AB-1
5.Put selector 7 B1 and 7 AB-1 to S/V (local).

This is P3B persons who lead the switching.