High Voltage Switching Program Template
v3.1
Purpose. Switching program writers use this template to set out the sequence of isolation, proving, earthing and restoration steps for planned high voltage work, ready for validation and direction by the network controller.
1.Purpose
The switching program is the single agreed plan for changing the state of the network. It must be complete, unambiguous and checked, because the controller and the field operator will perform exactly what it says.
2.Header information
Record the program number, the work order, the apparatus and feeder, the purpose of the outage, the planned start and finish, the customers affected and the notification sent, and the writer and checker.
3.Switching steps
Number every step. For each step record the location, the apparatus identification, the operation (open, close, prove de-energised, apply earth, remove earth, lock, tag), the operator, and the expected state. Write isolation steps, then proving and earthing, then the access authority issue point, then restoration in reverse.
- One operation per step
- Apparatus identified exactly as labelled in the field
- Proving before earthing
- Access authority issue and cancellation as numbered steps
- Restoration only after cancellation
4.Checks and validation
The writer checks the program against the network diagram and the access requirements. The checker independently confirms the sequence, the isolation points, the earths and the effect on customers and other work. Both sign in the switching program register.
5.Recording execution
During switching the controller records the time and the operator's confirmation against each step. Any deviation stops the program and is recorded in the notes with the duty manager's decision.