1SDH002031A1002 ECN000092998 Rev. B
SACE Tmax XT2
– XT4 | 37
S Protection
Function
If the current of one or more phases exceeds the I2 threshold, the protection is activated and,
after a time determined by the value read and the parameters set, it sends the TRIP command.
To verify and simulate the trip times based on all the parameters, see:
Protection summary table with the formulas for calculations (page 78)
Chart with tripping curve (page 84)
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
Function
Determines the curve dynamic and threshold or the calculation of
trip time:
t= k: trip at set time
t= k/I
2
: dynamic inverse time-delay trip
t= k
Threshold I2
Defines the value that activates protection and contributes to
calculating trip time.
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 t2
Depending on the type of curve selected, this is the trip time or
contributes to calculating timing.
The value is expressed in seconds, which are settable in a range:
0.05 s .. 0.4 s, with 0.01 s step
0.05 s
Thermal
memory
Activates/deactivates the thermal memory function, see page 70 for
details
NOTE: the function is available only with a curve t=k/I
2
OFF
Zone
Selectivity
Activates/deactivates the function and the display availability of
selectivity time, see page 70
for details
NOTE: the function is available only with curve t = k
OFF
Selectivity
time
This is the trip time of the protection with the zone selectivity
function active and the selectivity input not present see page 70for
details
The value is expressed in seconds, which are settable in a range:
0.04 s .. 0.2 s, with 0.01 s step
0.04 s
StartUp
enable
Activates/deactivates the function and display availability of the
combined parameters, see page 73
for details
OFF
StartUp
threshold
Protection threshold valid during Startup time, in conditions in which
the function is active, see page 73 for details
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
0.6 In
StartUp time
This is the time for which the StartUp threshold is active, calculated
from tripping of activation threshold, set details on page 73
The value is expressed in seconds, which are settable in a range:
0.1 s .. 30 s, with 0.01 s step
0.1 s
Constraints, limitations, and additional functions
The I2 threshold must be greater than the I1 threshold (if the S protection is active)
With curve t = k/I
2
the trip time is forced to t2 if the calculations result in a theoretical value
that is lower than t2 itself
Summary of Contents for SACE Tmax XT2
Page 84: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 84 L curve Ekip M Touch S curve t k I2 ...
Page 86: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 86 G curve t k I2 G curve t k ...
Page 87: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 87 IU curve UV curve UV2 curve ...
Page 88: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 88 OV curve OV2 curve VU curve ...
Page 89: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 89 S V curve S2 V curve RV curve ...
Page 90: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 90 UF curve UF2 curve OF curve OF2 curve ...
Page 91: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 91 RP curve D curve ...
Page 92: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 92 OQ curve OP curve ...
Page 93: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 93 UP curve RQ curve ...
Page 94: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 94 ROCOF curve R JAM curve R STALL ...
Page 95: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 95 UC curve ...
