Stub Protection Stbptoc (50Stb) - ABB REC650 ANSI Technical Manual

Section 6
Current protection
6.8
6.8.1
6.8.2
6.8.3
142
Function
Reset ratio
Timers
Operate time for current
detection
Reset time for current
detection

Stub protection STBPTOC (50STB)

Identification
Function description
Stub protection
Functionality
When a power line is taken out of service for maintenance and the line disconnector is
opened, line side voltage transformers will be on the disconnected part of the line. The
primary line distance protection will thus not be able to operate and must be blocked.
The stub protection STBPTOC (50STB) covers the zone between the current transformers
and the open disconnector. The three-phase instantaneous overcurrent function is released
from a normally open, 89b auxiliary contact on the line disconnector.
Function block
STBPTOC (50STB)
I3P* TRIP
BLOCK PICKUP
ENABLE
ANSI08000051-1-en.vsd
ANSI08000051 V1 EN
Figure 57: STBPTOC (50STB) function block
Range or value
> 95%
(0.000-60.000) s
20 ms typically
10 ms maximum
IEC 61850
identification
STBPTOC
1MRK 511 287-UUS A
Accuracy
-
± 0.5% ±10 ms
-
-
IEC 60617 ANSI/IEEE C37.2
identification device number
50STB
3I>STUB
SYMBOL-T V1 EN
Technical manual