ABB RELION RET670 - Permissive Underreache Scheme

Configure the zones used for the CS carrier send and for scheme communication
tripping by using the Application Configuration tool. The recommended settings of
tCoord
timer are based on maximal recommended transmission time for analog
channels according to IEC 60834-1. It is recommended to coordinate the proposed
settings with actual performance for the teleprotection equipment to get optimized
settings.
16.2.3.1 Permissive underreache scheme
SEMOD141800-6 v1
Set
Operation = On
Set Scheme
type
= Permissive UR
Set tCoord = 0 ms
Set
tSendMin = 0.1 s
16.2.3.2 Permissive overreach scheme
SEMOD141800-9 v1
Set
Operation = On
Set Scheme
type
= Permissive OR
Set tCoord = 0 ms
Set
tSendMin = 0.1 s
16.2.3.3 Blocking scheme
SEMOD141800-12 v1
Set Operation = On
Set Scheme
type
= Blocking
Set tCoord = 25 ms (10 ms + maximal transmission time)
Set
tSendMin = 0 s
16.2.3.4 Intertrip scheme
SEMOD141800-15 v1
Set
Operation = On
Set Scheme
type
= Intertrip
Set tCoord = 50 ms (10 ms + maximal transmission time)
Set
tSendMin = 0.1 s
1MRK 504 163-UUS A Section 16
Scheme communication
Transformer protection RET670 2.2 ANSI 825
Application manual