D Protection - ABB SACE Emax E1.2 Operating Instructions For The Design Engineer

D Protection

t
D
I7
t7bw
t7fw
83 | © 2017 ABB | 1SDH001330R0002 - ECN000058721 Rev. A
Path
Main page - Menu - Advanced
Function
D protection protects against selective directional short circuit.
Once the activation threshold has been exceeded, the protection trips within a fixed time determined by the
direction of the fault, t7fw in the case of forward direction and T7bw in the case of backward direction.
Operating principle
I
The direction of the fault current detected is compared with the reference direction for the fault
current (forward direction).
This reference direction matches the set power flow value in nominal conditions, provided that the phase
sequence has been set correctly (cyclic direction of the phases).
Cyclic direction of
the phases (Set)
123
123
123
123
321
321
321
321
NOTE: The flow of power parameter is described under the Ekip Measuring Pro module, on
page 179, while the phase sequence on page 79.
Parameters
It is possible to modify various parameters:
Parameter
Enable
Threshold I7 Bw
Threshold I7 Fw
Time t7 Fw
Time t7 Bw
Direction Min Angle
Cyclic direction of
Power flow
the phases (Real)
Top -> Bottom 123
Bottom -> Top 123
Top -> Bottom 321
Bottom -> Top 321
Top -> Bottom 123
Bottom -> Top 123
Top -> Bottom 321
Bottom -> Top 321
Description
To activate/deactivate the protection.
It defines the current value that activates the protection when exceeded (with
reference to the figure above, the threshold is the part of the curve parallel to
the y-axis), in the case of forward direction.
It is represented both as an absolute value (Ampere) and as a relative value (In,
nominal value defined by the Rating Plug)
It defines the current value that activates the protection when exceeded (with
reference to the figure above, the threshold is the part of the curve parallel to
the y-axis), in the case of backward direction.
It is represented both as an absolute value (Ampere) and as a relative value (In,
nominal value defined by the Rating Plug)
This is the delay time between the exceeding of the I7 threshold and the
sending of the opening command, in the case of forward direction.
This is the delay time between the exceeding of the I7 threshold and the
sending of the opening command, in the case of backward direction.
The direction of the fault is calculated by the trip unit according to the phase
difference angle between the reactive and apparent powers measured:
when the phase-difference becomes greater than the parameter Min Angle
Direction set, the trip unit considers the direction of the fault to have been
identified.
NOTE: There are 15 preset values available, in a range from 3.6° to
69.6°.
ABB | SACE Emax 2
Reference direction for
the fault current
(forward direction).
Top -> Bottom
Bottom -> Top
Bottom -> Top
Top -> Bottom
Bottom -> Top
Top -> Bottom
Top -> Bottom
Bottom -> Top
Continued on the next page
Ekip Touch protection trip unit | 11 - Hi-Touch protections