ABB SACE Tmax XT5 Operation And Maintenance Manual page 63

D Protection
t
D
I7
t7bw
t7fw
61 | © 2019 ABB | 1SDH002039A1002 - ECN000093027 - Rev. A
Function
D protection is very similar to S protection, with the additional capability of recognizing the direction of the
current during a fault.
The current direction allows the user to find out whether the fault is on the supply side or load side of the
device controlled by Ekip Touch.
In ring type distribution systems, D protection allows the distribution section in which the fault has occurred
to be identified and disconnected without affecting the rest of the installation (using zone selectivity).
Depending on the direction of the fault, if the current of one or more phases exceeds threshold I7 (fw or bw)
I
for longer than time t7 (fw or bw), the protection activates and sends a TRIP command.
The fault direction is established by comparing the detected fault current with the reference direction.
NOTE: the reference direction is calculated considering the set value of the power flow
direction and the phase sequence (cyclic direction of the phases):
Phase sequence (set) Power flow (set)
123
123
123
123
321
321
321
321
To check and simulate the trip times in relation to all the parameters, please consult:
• the summary table of the protections with the calculation formulas (page 80)
• the graph with trip curve (page 92)
Parameter Description
Activates/deactivates the protection and its availability in the parameters
Enable
menu
Activates/deactivates transmission of the open command: if disabled, the
Trip Enable
alarm and exceedance of protection time are only managed as information
Establishes the value that activates the protection with forward direction.
The value is given as both absolute value (Amperes) and relative value (In)
Threshold I7 Fw
and can be set within the range: 0.6 In to 10 In, in 0.1 In steps
Establishes the value that activates the protection with backward direction.
Threshold i7
The value is given as both absolute value (Amperes) and relative value (In)
Bw
and can be set within the range: 0.6 In to 10 In, in 0.1 In steps
This is the trip time in the case of forward direction.
The value is given in seconds and can be set within the range: 0.1 s to 0.8
Time t7 Fw
s, in 0.01 s steps
This is the trip time in the case of backward direction.
The value is given in seconds and can be set within the range: 0.1 s to 0.8
Time t7 Bw
s, in 0.01 s steps
Activates/deactivates the function and selectivity time availability on the
display.
ZoneSelectivity
NOTE: configure selectivities S, S2 OFF to ensure that selectivity D
(1)
functions correctly and G
This is the trip time of the protection with the zone selectivity function
activated, forward direction and selectivity input Fw not present.
Selectivity time
Fw The value is given in seconds and can be set within the range: 0.1 s to 0.8
(1)
s, in 0.01 s steps
This is the trip time of the protection with the zone selectivity function
Selectivity time activated, backward direction and selectivity input Bw not present.
Bw The value is given in seconds and can be set within the range: 0.1 s to 0.8
(1)
s, in 0.01 s steps
Phase sequence
(detected)
High-->Low 123
Bottom --> Top 123
High-->Low 321
Bottom --> Top 321
High-->Low 123
Bottom --> Top 123
High-->Low 321
Bottom --> Top 321
ABB | SACE Tmax XT
Reference direction
(forward direction)
High-->Low
Bottom --> Top
Bottom --> Top
High-->Low
Bottom --> Top
High-->Low
High-->Low
Bottom --> Top
Default
OFF
ON
4 In
4 In
0,2 s
0,2 s
OFF
0,13 s
0,13 s
Continued on the next page
Protections | 5 - Power protections