Page 71 - MCCB-XT2-XT4

Continued from the previous page ABB | SACE Tmax XT
Configuration
To correctly configure selectivity D in a ring system:
1. Connect the zone selectivity outputs of each device (example: DFin) to the selectivity input of the same
direction as the device immediately after (example: DFout).
2. Connect all the Szc of devices in the same network together.
Logic table
The table includes all cases in which, with zone selectivity enabled in the device, an alarm condition occurs
or a zone selectivity signal is received from another device.
The Forward output is activated if the fault direction coincides with the reference direction otherwise, if
it is in the opposite direction, the Backward output is activated (page 56)
Fault di- Tripping
rection Condition DFin Dbin Dfout Dbout time Remarks
Forward If < I7 Fw 0 x 0 x No TRIP Device not in alarm status
Backward If < I7 Bw x 0 x 0
Forward If < I7 Fw 1 x 1 x The device is not in the alarm
status, but sends the selecitivity
No TRIP
Backward If < I7 Bw x 1 x 1 signal received to the output of the
reference direction
Forward If > I7 Fw 0 x 1 x t7 Fw sel The device is in the alarm status and
is the first to detect the fault: trips
Backward If > I7 Bw x 0 x 1 t7 Bw sel
within time t7 Fw sel or t7 Bw sel
Forward If > I7 Fw 1 x 1 x t7 Fw The device is in the alarm status but
is not the first to detect the fault:
Backward If > I7 Bw x 1 x 1 t7 Bw
trips within time t7 Fw (or t7 Bw)

NOTE: when zone selectivity is active and the direction of the fault cannot be established,
the unit trips by considering the first threshold to be exceeded between I7 Fw and I7 Bw,
without activating any output (DFout or Dbout).; if both the thresholds have been exceeded
(for example, if they have been set with the same value), the unit trips after the shortest
time between t7 Fw and t7 Bw.

Trip Only Forward and D protection can be configured (if available and enabled) with 2 additional parameters via the service
Backward connector (via Ekip Connect) or via system bus communication:
• Trip only Forward: if activated, D protection only controls open commands if forward direction is
detected
• Trip only Backward: if activated, D protection only controls open commands if backward direction
is detected
faults in the opposite direction are only handled as alarm information.

Type of selectivity The zone selectivity inputs and certain of the outputs can be configured via service connector (via Ekip
Connect) or via system bus communication for protections S, S2, I, 2I, MCR, G and D (if available and
enabled):
• Standard: operation as by zone selectivity standard logic (default configuration)
• Customized: the event that activates the zone selectivity input or output can be selected in this mode.
IMPORTANT: in the Customized configuration, the only zone selectivity activation event
is the one set and standard selectivity operation is therefore not active (changes should
only be made by expert technical personnel).

69 | © 2022 ABB | 1SDH002031A1002 - ECN000212994 Protections | 10 - Additional protections and functions