ABB RELION 670 Series Applications Manual page 120

Section 6
Differential protection
IEC06000227 V1 EN-US
Figure 52: Principal trip arrangement via GOOSE between three one-phase IEDs
6.1.3.14 Centralized trip unit
Tripping is performed directly from the IED contacts, which then activate an auxiliary trip unit,
which multiplies the number of required trip contacts. Separate potential free contacts are
provided for each bay and are supplied by the bay auxiliary voltage and will activate the trip coil of
each bay circuit breaker at operation. This tripping setup is suitable when no individual circuit
breaker failure IEDs or lock-out of individual bay CB closing coils is required. A suitable external
trip unit consists of a combination of RXMS1/RXMH 2 alternatively AR/MG6 when heavy duty
contacts are required and only RXMS 1/AR relays when medium duty contacts are sufficient.
6.1.3.15 Decentralized trip arrangement
Tripping is performed directly from the IED contacts, which then activate dedicated auxiliary trip
unit per bay. This individual auxiliary trip unit can be mounted either in the busbar protection
cubicle or in the individual bay cubicles. This tripping setup is suitable when individual circuit
breaker failure relays exist in all bays. A suitable external trip unit consists of a combination of
RXMS1/RXMH 2 alternatively AR/MG6 when heavy duty contacts are required and only RXMS 1/AR
relays when medium duty contacts are sufficient.
This solution is especially suitable for the station arrangements, which require the dynamic zone
selection logic (that is, so called CT switching).
6.1.3.16 Mechanical lock-out function
114
ZoneA Trip
IED 670
ZoneB Trip
50 ms
Ext ZoneA Trip
IED 670
50 ms
Ext ZoneB Trip
50 ms
Ext ZoneA Trip
IED 670
50 ms
Ext ZoneB Trip
t
GOOSE for ZoneA
GOOSE for ZoneB
Switch
en06000227.vsd
1MRK 505 337-UUS A
M12117-3 v1
M12117-4 v3
M12118-3 v1
M12118-4 v3
M12119-3 v1
Application manual