LOP versus Supply Timeout Example
Consider a situation where the following settings are applied:
-
LOP Protection – Trip
-
LOP Voltage – 2000 V
-
LOP Timeout – 10.0 s
-
Live Line Threshold – 2000 V
-
Supply Timeout – 4.0 s
And on a feeder energized at 6300 V per phase to earth, A phase goes dead at 00:00:00.00
The following events would be logged:
|
Time |
Event |
Cause |
|---|---|---|
|
00:00:04.00 |
A1 Dead |
A phase bushings recorded as dead when Supply Timeout expires after 4s. |
|
00:00:04.00 |
A2 Dead |
|
|
00:00:10.00 |
A Phase LOST |
LOP protection operates 6 s later when the LOP Timeout expires. |
|
00:00:10.00 |
Protection Trip Request |
LOP issues a trip request to the switchgear. |
The same sequence of events are shown in the timing diagram below.
