ABB Relion 670 Series Applications Manual page 554

Section 21
Station communication
IEC08000069 V2 EN-US
Figure 265: Example of a station configuration with the IED receiving analog values from
21.3.2 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. Also, protection functions configured in a 1 1/2 circuit
breaker applications, where two SV streams from different merging units are combined get
blocked. Thus, this has no effect on protection functions in a 1 1/2 circuit breaker
configuration.
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.
548
Station Wide
SCADA System
Other
Relays
CT
both classical measuring transformers and merging units.
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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
1MRK 511 401-UEN Rev. K
Station Wide
GPS Clock
Splitter
Electrical-to-
Optical Converter
1PPS
1PPS
en08000069-3.vsd
GUID-CBAB6232-91E6-487C-8C75-7150E2350A6B v1
Bay control REC670
Application manual