Switching Programs Terminology & Abbreviations
Before starting to write a switching program, it is important to understand and use standard terminology. The table below includes some common fields found on templates.
| Program Field | Meaning |
| Program number | This is obtained from the operating authority |
| Written By | An operator who is authorised to carry out the operations within the program |
| Checked By | An operator same as above |
| Dates | The date the program was written and the date it was checked |
| Copies To | List of persons or places to receive copies of the program |
| Item | This is a sequential list of numbers for each operation to be carried out |
| Location – Instructions | Refers to the location of the equipment to be operated and any special instruction required |
| Plant | Names the plant to be operated |
| Operation | Describe the operation to be carried out on the named plant |
| Time | Precise time operation was carried out |
| Voltage | Highest voltage that operations will be carried out at |
| Sheet Number | Sheets are to be numbered; e.g. 1 of 3, 2 of 3, 3 of 3 |
| Substation | Refers to any substations where circuits are affected by the program |
| Circuit | Name of the circuit that operations are being carried out upon |
| Section to be Isolated | A brief description of the section |
| Work to be Carried Out | Briefly describe the purpose of the program |
| Operator in Charge | Is the authorised operator who will carry out the program, or the operator who will control other operations on the program |
Only standard accepted terms should be used on the program. Below is a table of standard terminology used when developing switching programs.
| Term | Action Required |
| AUTO | Switch a control to an automatic position |
| BOTTOM BUS | The busbar at the bottom of metal clad switchgear |
| BUS COUPLER | A switching device that connects two different busbars together |
| BUS TIE | A switching device that connects sections of the same busbar together |
| CABLE | An underground cable. |
| COMPOUND | Ground mounted transformer |
| D/L | Fitting of danger label to equipment to warn against operation. |
| EARTH. | Placement of portable earths or closing an earth switch to ON. |
| FRONT BUS | The busbar closest to the front of metal clad switchgear. |
| ISOLATED | To disconnecting equipment from all sources of supply. |
| MANUAL | Switch a control to a manual position |
| MANUAL FIX TAPS | Switching the control of automatic tap changes to manual and alteration of taps for equalisation of volts. |
| OFF | Where a switch is put in the position or condition where contacts are open and current cannot flow. |
| ON | When a switch is in a position where contacts are closed & current can pass through. |
| PADMOUNT | A pad mount type substation or kiosk |
| R D/L | Removal of a danger label |
| RACK DOWN | The physical disconnection of a metal clad OCB or ACB from the busbar. |
| RACK UP | The physical connection of a metal clad OCB or ACB to the busbar |
| REAR BUS | The busbar furthest from the front of metal clad switchgear |
| REMOVE EARTH | Portable earths removed from equipment |
| TOP BUS | The busbar at the top of metal clad switchgear. |
You also need to be aware of common abbreviations used on switching programs. It is critical that all personnel involved with the program understand the abbreviations correctly.
| Abbreviation | Description |
| A/R | Auto Reclose |
| ABS | Air Break Switch |
| ACB | Air Circuit Breaker |
| CL | Caution Label (Vicinity Work in Progress) |
| CT | Current Transformer |
| DL | Danger Label |
| DOF | Drop Out Fuse |
| E/SW or E/S | Earthing Switch |
| EAP | Electrical Access Permit |
| GCB | Gas Circuit Breaker |
| GMTX or PMT | Ground Mounted Transformer or Padmount Transformer |
| HV | High Voltage |
| ISOL | Isolator |
| K/SW | Knife Switch |
| LA | Lightning Arrestor |
| LDC | Line Drop Compensator |
| LV | Low Voltage |
| MS | Main Switch |
| OCB | Oil Circuit Breaker |
| OLTC | On Load Tap Changer |
| OSF | Oil Switch Fuse |
| PMTX or PTT | Pole Mounted Transformer |
| PTS | Pole Top Switch |
| R/IN | Rack In |
| R/OUT | Rack Out |
| RCL | Remove Caution Label |
| RD | Rack Down |
| RDL | Remove Danger Label |
| REC | Recloser |
| RIC | Recipient in Charge |
| RM/ES | Ring Main Earth Switch |
| RM/IS | Ring Main Isolator |
| RMU | Ring Main Unit |
| RU | Rack Up |
| SMTX | Skid Mounted Transformer |
| STT | Sanction to Test |
| SW | Switch |
| TX | Transformer |
| VA | Vicinity Authority |
| VCB | Vacuum Circuit Breaker |
| VT | Voltage Transformer |
