ABB | SACE Tmax XT
Protections | 7 - Standard Protections
45 | © 2020 ABB | 1SDH001821A1002 - ECN000135670
S Protection
S
I2
t
t2
I
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 87)
• the graph with trip curve (page 94)
Parameters
Parameter
Description
Default
Enable
Activates/deactivates the protection and its availability in the
parameters menu.
OFF
Trip Enable
Activates/deactivates transmission of the open command. if disabled,
the alarm and exceedance of protection time are only managed as
information.
ON
Curve
Establishes curve dynamics and the threshold or trip time calculation:
• t = k: fixed time trip
• t = k/I
2
: inverse time-delay dynamic trip
t = k
Threshold I2
Establishes the value that activates the protection and contributes
towards calculating the trip time.
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
4 In
Time t2
It is the trip time or contributes towards timing calculation, depending
on the type of curve selected.
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
0,05 s
Thermal
memory
Activates/deactivates the thermal memory function (page 75)
NOTE
:the function is only available with curve t=k/I
2
OFF
ZoneSelectivity
Activates/deactivates the function and selectivity time availability on
the display (page 75)
NOTE
:the function is only available with curve t=k
OFF
Selectivity time
This is the trip time of the protection with the zone selectivity function
activated and selectivity input not present (page 75)
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
0,04 s
StartUp enable
Activates/deactivates the function and availability of the associated
parameters on the display (page 78)
OFF
StartUp
Threshold
Protection threshold valid during Startup time, in the conditions in
which the function is activated (page 78)
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
0,6 In
StartUp Time
This is the time for which the StartUp threshold remains activated and
is calculated from the moment the activation Threshold is exceeded
(page 78)
The value is given in seconds and can be set within the range: 0.1 s to
30 s, in 0.01 s steps
0.1 s
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
2
, the protection trip time is forced to t2 if the calculation results give a
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 75)
• with CB in UL standard configuration, the maximum value of t2 is 400 ms
