Hitachi Relion 670 Series Applications Manual page 374

Section 18
Station communication
IEC08000069 V2 EN-US
Figure 186:
18.3.2 Faulty merging unit for bay in service
When a merging unit goes faulty while the bay is in service, the protection functions connected to
that merging unit get blocked.
This can be resolved by connecting external binary input signals to the BLOCK input on the
respective SMAI function blocks with the use of ACT. When the BLOCK input on a SMAI function is
energized, the SMAI function delivers a magnitude of zero with good quality for all the channels.
Thus, this has no effect on a busbar protection, nor protections in an 1 1/2 circuit breaker
configuration.
368
Station Wide
SCADA System
Other
Relays
CT
Example of a station configuration with the IED receiving analog values from both
classical measuring transformers and merging units.
SMAI function blocks exist in different cycle times, and all the SMAI blocks that receive
SV streams from the merging units must have the block input signal configured in the
same way to get the correct behavior.
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IEC61850-8-1
IEC61850-8-1
110 V
IED
1 A
1 A
IEC61850-9-2LE
Ethernet Switch
IEC61850-9-2LE
ABB
Merging
Unit
Combi
CT
Sensor
Conventional VT
1MRK506375-UEN Rev. N
Station Wide
GPS Clock
Splitter
Electrical-to-
Optical Converter
1PPS
1PPS
en08000069-3.vsd
GUID-CBAB6232-91E6-487C-8C75-7150E2350A6B v2
Railway application RER670
Application manual