ABB ret650 - Page 319

IEC13000298-2-en.vsd
IEDIED
MU
OK
OK
Direct transfer trip (DTT)
local remote
IEC13000298 V2 EN-US
Figure 112: Normal operation
Case 2:
Failure of the MU (sample lost) blocks the sending of binary signals through
LDCM. The received binary signals are not blocked and processd normally.
→DTT from the remote end is still processed.
IEC13000299-2-en.vsd
Direct transfer trip (DTT)
local remote
IEDIED
MU
Not OK
OK
IEC13000299 V2 EN-US
Figure 113: MU failed, mixed system
Case 3:
Failure of one MU (sample lost) blocks the sending and receiving of binary signals
through LDCM.
→DTT from the remote end is not working.
1MRK 504 169-UEN A Section 16
Station communication
Transformer protection RET650 2.2 IEC 313
Application manual