ABB Relion 670 Series Applications Manual page 460

Section 18
Remote communication
possible to use LDCM communication modules to effectively share the binary Ios between three units, as
shown in figure 233233.
Wire status of
disconnectors
from Bays 01-08
Wire status of
disconnectors
from Bays 09-16
Wire status of
disconnectors
from Bays 17-24
IEC06000198 V2 EN-US
Figure 233: Example how to share binary IO between one-phase REB670 IEDs by using LDCM
As shown in figure 233, it is possible to wire only the status for bays 01-08 to A phase-IED. After that the
information about auxiliary contact status for switchgear objects from these eight bays can be sent via
LDCM modules to other two phases. In the similar way information from other bays can be only wired to
B, respectively C phase IED and then shared to the other two phases via LDCM communication.
Typical LDCM communication delay between two IEDs is in order of 30-40 ms. Note that for disconnector
status this delay will not pose any practical problems. However, time delay caused by LDCM
communication can be crucial for circuit breakers status. In such cases it is strongly recommended that
at least the circuit breaker closing command from every circuit breaker is directly wired to all three
phases/IEDs to minimize any risk for unwanted operation of the busbar differential protection zones due
to late inclusion of respective bay current into the differential measuring circuit.
18.1.3 Setting guidelines
64 kbit mode common settings
ChannelMode defines how an IED discards the LDCM information when one of the IEDs in the system is
out of service: it can either be done on the IED out of service by setting all local LDCMs to channel mode
OutOfService or at the remote end by setting the corresponding LDCM to channel mode Blocked. If
454
REB 670, B31
Phase L1
REB 670, B31
Phase L2
REB 670, B31
Phase L3
modules
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1MRK 505 370-UUS Rev. K
<= 192 Binary Signals =>
<= 192 Binary Signals =>
<= 192 Binary Signals =>
en06000198.vsd
Busbar protection REB670
M12454-3 v10
Application manual