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 |