ABB SACE Tmax XT2 User Manual

1SDH002031A1002 ECN000092998 Rev. B SACE Tmax XT2 – XT4 | 58
D Protection
Function
D Protection is very similar to S protection plus the ability to recognize current direction during
the malfunction period.
The direction of the current allows detecting if the malfunction is upstream or downstream of the
device controlled by Ekip Touch.
In ring distribution systems, D protection makes it possible to identify the distribution section
where the malfunction occurred and to isolate it without affecting the rest of the system (using
zone selectivity).
Depending on the direction of the malfunction, if the current of one or more phases exceeds the
I7 threshold (fw or bw) for a time greater than t7 (fw or bw), the protection is activated and sends
the TRIP command.
The direction of the malfunction is determined by comparing the direction of the malfunction
current detected with the direction of reference.
NOTE: the direction of reference is calculated by considering the value set for the
power flow direction and the phase sequence (cyclical direction of the phases):
Sequence of
phases set
Power flow set
Sequence of
phases detected
Reference direction
(forward direction)
123
High  Low
123
High  Low
123
Low  High
123
Low  High
123
High  Low
321
Low  High
123
Low  High
321
High  Low
321
High  Low
123
Low  High
321
Low  High
123
High  Low
321
High  Low
321
High  Low
321
Low  High
321
Low  High
To verify and simulate the trip times based on all the parameters, see:
 Protection summary table with the formulas for calculations (page 79)
 Chart with tripping curve (page 91)
Parameters
Parameter
Description
Default
Enable
Enables/disables protection and availability on menu of the parameters
OFF
Trip Enable
Activates/deactivates the open command: if disabled, the alarm and the
lapsing of the protection time are managed only as information
ON
Threshold I7
Fw
Defines the value that activates the protection in the event of a forward
direction.
The value is expressed both as an absolute value (Ampere) and as a
relative value (In), settable in a range: 0.6 In .. 10In with 0.1 In step
2 In
Threshold I7
Bw
Defines the value that activates the protection in the event of backward
direction.
The value is expressed both as an absolute value (Ampere) and as a
relative value (In), settable in a range: 0.6 In .. 10In with 0.1 In step
2 In
Time t7 Fw
This is the intervention time in the event of a forward direction.
The value is expressed in seconds, which are settable in a range:
0.1 s .. 0.8 s, with 0.01 s step
0.2 s
Time t7 Bw
This is the trip time in a backward direction.
The value is expressed in seconds, settable in a range:
0.1 s .. 0.8 s, with 0.01 s step
0.2 s

ABB SACE Tmax XT2 Specifications

General

Brand	ABB
Model	SACE Tmax XT2
Category	Circuit breakers
Language	English