ABB SACE Tmax XT5 Operation And Maintenance Manual page 43

S Protection
t
I2 S
t2
41 | © 2019 ABB | 1SDH002039A1002 - ECN000093027 - Rev. A
Function
If the current of one or more phases exceeds threshold I2, the protection trips and, after a time established
by the value read and by the parameter settings, transmits the TRIP command.
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 79)
• the graph with trip curve (page 85)
Parameters
I
Parameter Description
Activates/deactivates the protection and its availability in the
Enable
parameters menu.
Activates/deactivates transmission of the open command. if disabled,
Trip Enable the alarm and exceedance of protection time are only managed as
information.
Establishes curve dynamics and the threshold or trip time calculation:
Curve • t = k: fixed time trip
• t = k/I
Establishes the value that activates the protection and contributes
towards calculating the trip time.
Threshold I2
The value is given as both absolute value (A) and relative value (In) and
can be set within the range: 0.6 In to 10 In, in 0.1 In steps
It is the trip time or contributes towards timing calculation, depending
on the type of curve selected.
Time t2
The value is given in seconds and can be set within the range: 0.05 s
to 0.8 s, in 0.01 s steps
Activates/deactivates the thermal memory function (page 72)
Thermal
NOTE:the function is only available with curve t=k/I
memory
Activates/deactivates the function and selectivity time availability on
the display (page 72)
ZoneSelectivity
NOTE:the function is only available with curve t=k
This is the trip time of the protection with the zone selectivity function
activated and selectivity input not present (page 72)
Selectivity time
The value is given in seconds and can be set within the range: 0.04 s
to 0.2 s, in 0.01 s steps
Activates/deactivates the function and availability of the associated
StartUp enable
parameters on the display (page 75)
Protection threshold valid during Startup time, in the conditions in
StartUp which the function is activated (page 75)
Threshold The value is given as both absolute value (A) and relative value (In) and
can be set within the range: 0.6 In to 10 In, in 0.1 In steps
This is the time for which the StartUp threshold remains activated and
is calculated from the moment the activation Threshold is exceeded
StartUp Time (page 75)
The value is given in seconds and can be set within the range: 0.1 s to
30 s, in 0.01 s steps
Limitations and additional functions
• threshold I2 must be higher than threshold I1 (if S protection is activated)
• in the presence of curve t= k/I
theoretical value lower than t2 itself
• the block functions and type of selectivity can also be accessed by means of the service connector (via
Ekip Connect) or communication via system bus (page 72)
: inverse time-delay dynamic trip
2
, the protection trip time is forced to t2 if the calculation results give a
2
ABB | SACE Tmax XT
Default
OFF
ON
t = k
4 In
0,05 s
OFF
2
OFF
0,04 s
OFF
0,6 In
0.1 s
Protections | 1 - Standard Protections