Appendix L.1 Loop Automation Operating Rules
In the following tables, the Sequence (Seq.) column indicates if the rule is applied during Isolation and Reconfiguration (I) or during Auto Restoration (R).
Feeder Device
Table 149 Loop Automation operating rules – Feeder Device
|
Rule No |
Switchgear State |
Auto-Restore |
Event |
Action |
Seq. |
|---|---|---|---|---|---|
|
1 |
Closed |
Off |
Source Supply lost for longer than Loop Auto Time. |
Switchgear opens and Loop Automation is turned off. |
I |
|
2 |
Closed |
On |
Source Supply lost for longer than Loop Auto Time. |
Switchgear opens. |
I |
|
3 |
Closed |
Off |
Protection trip to Lockout. |
Switchgear opens and Loop automation is turned off. |
I |
|
4 |
Closed |
On |
Protection trip to end of sequence. |
Switchgear opens and Loop Automation stays on. |
I |
|
5 |
Open |
On |
Source Supply is restored and switchgear was initially tripped by Loop Automation. |
Switchgear closes. |
R |
|
6 |
Open |
On |
Supply is restored to both sides of the switchgear. Either at the source then load or load then source. |
Switchgear closes. |
R |
Mid-Point Device
Table 150 Loop Automation operating rules – Mid-Point Device
|
Rule No |
Switchgear (ACR) State |
Auto-Restore |
Event |
Action |
Seq. |
|---|---|---|---|---|---|
|
7 |
Closed |
On or Off |
Source Supply lost for longer than Loop Auto Time. |
Switch to reverse Protection Group |
I |
|
8 |
Closed |
Off |
Protection trip to Lockout. |
ACR opens and Loop Automation is turned off. |
I |
|
9 |
Closed |
On |
Protection trip to end of sequence. |
ACR opens and Loop Automation stays on. |
I |
|
10 |
Open |
On |
Supply is restored to both sides of ACR. |
Switch to forward Protection Group and close ACR. |
R |
Tie Device
Table 151 Loop Automation operating rules – Tie Device
|
Rule No |
Switchgear State |
Auto-Restore |
Restore Both Ways |
Event |
Action |
Seq. |
|---|---|---|---|---|---|---|
|
11 |
Open |
On or Off |
On or Off |
Supply to both sides is lost for longer than Loop Auto Time. |
No Action |
I |
|
12 |
Open |
On |
On or Off |
Supply to load side is lost for longer than Loop Auto Time. |
Switchgear closes if alternative supply is present. |
I |
|
13 |
Open |
Off |
On or Off |
Supply to load side is lost for longer than Loop Auto Time. |
Switchgear closes if alternative supply is present and turns Loop Automation off. |
I |
|
14 |
Open |
On |
On |
Supply to source side is lost for longer than Loop Auto Time. |
Activates reverse Protection Group and closes switchgear. |
I |
|
15 |
Open |
Off |
On |
Supply to source side is lost for longer than Loop Auto Time. |
Activates reverse Protection Group, closes switchgear and turns Loop Auto off. |
I |
|
16 |
Open |
On or Off |
Off |
Supply to source side is lost for longer than Loop Auto Time. |
No Action. |
I |
|
17 |
Closed |
On |
On or Off |
Protection trip to Lockout. |
Switchgear opens and Loop Automation is turned off. |
I |
|
18 |
Closed |
On |
On or Off |
Power flow changes by 50% or more for Loop Auto Time. |
Switchgear opens. (If supply is subsequently lost to either side then switchgear closes and Loop Automation turns off.) |
R |
|
19 |
Closed |
On |
On or Off |
Power flow changes by 50% or more but returns to previous level before Loop Auto Time expires. |
Switchgear stays closed and Loop Automation is turned off. |
R |