ABB RELION 670 Series Applications Manual page 701

1MRK 504 152-UEN B
TransmCurr : This setting decides which of 2 possible local currents that shall be transmitted,
or if and how the sum of 2 local currents shall be transmitted, or finally if the channel shall be
used as a redundant channel.
In a 1½ breaker arrangement, there will be 2 local currents, and the earthing on the CTs can be
different for these.
group 1 minus CT group 2 and
CT-GRP1 or CT-GRP2 will transmit the respective CT group, and the setting RedundantChannel
makes the channel be used as a backup channel.
ComFailAlrmDel : Time delay of communication failure alarm. In communication systems, route
switching can sometimes cause interruptions with a duration up to 50 ms. Thus, a too short
time delay setting might cause nuisance alarms in these situations.
ComFailResDel : Time delay of communication failure alarm reset.
RedChSwTime : Time delay before switchover to a redundant channel in case of primary
channel failure.
RedChRturnTime : Time delay before switchback to a the primary channel after channel failure.
AsymDelay : The asymmetry is defined as transmission delay minus receive delay. If a fixed
asymmetry is known, the
AsymDelay is properly set. From the definition follows that the asymmetry will always be
positive in one end, and negative in the other end.
AnalogLatency : Local analog latency; A parameter which specifies the time delay (number of
samples) between actual sampling and the time the sample reaches the local communication
module, LDCM. The parameter shall be set to 2 when transmitting analog data from the .
RemAinLatency : Remote analog latency; This parameter corresponds to the LocAinLatency set
in the remote IED.
MaxTransmDelay : Data for maximum 40 ms transmission delay can be buffered up. Delay
times in the range of some ms are common. It shall be noticed that if data arrive in the wrong
order, the oldest data will just be disregarded.
CompRange : The set value is the current peak value over which truncation will be made. To set
this value, knowledge of the fault current levels should be known. The setting is not overly
critical as it considers very high current values for which correct operation normally still can be
achieved.
MaxtDiffLevel : Allowed maximum time difference between the internal clocks in respective line
end.
Application manual
CT-SUM will transmit the sum of the 2 CT groups. CT-DIFF1 will transmit CT
CT-DIFF2 will transmit CT group 2 minus CT group 1.
Echo synchronization method can be used if the parameter
Section 20
Remote communication
695