ABB SACE Tmax XT2 User Manual page 40

G Protection Function
Ekip Touch executes the vectorial sum of the phase currents (L1, L2, L3, Ne) obtaining the
internal ground fault current (I
activated and, after a time determined by the value detected and the parameters set, it sends the
TRIP command.
To verify and simulate the trip times based on all the parameters, see:


Parameters
Parameter
Enable
Trip Enable
Function
Threshold I4
Time t4
Pre-alarm I4
Zone
Selectivity
Selectivity
time
StartUp
enable
StartUp
threshold
StartUp time
1SDH002031A1002 ECN000092998
Protection summary table with the formulas for calculations (page 78)
Chart with tripping curve (page 86, 86)
Description
Enables/disables protection and availability on menu of the parameters
Activates/deactivates the open command: if disabled, the alarm and the
lapsing of the protection time are managed only as information
Determines the curve dynamic and threshold or the calculation of trip time:

t= k: trip at set time

2
t= k/I : dynamic inverse time-delay trip
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:
0.1 In .. 1In with 0.001 In step
On the basis of the selection of the curve type, it is the trip time and
contributes to calculating timing.
The value is expressed in seconds, which are settable in a range:
0.1 s .. 1 s with 0.05 s step
NOTE: with curve: t= k, t4 can also be configured as:
instantaneous; in this mode the trip time is comparable with the
trip time declared for protection I, see page 78 for details
Enables a warning to be sent that the measured current is near the
threshold triggering the protection.
The value is expressed as a percentage of the threshold I1, which is
settable in a range: 50 % I4 .. 90 % I4, with 1 % step
The pre-alarm threshold is deactivated in two cases:

current below pre-alarm threshold I4

current above threshold I4
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
This is the trip time of the protection with the zone selectivity function active
and the selectivity input not present see page 70 for details
The value is expressed in seconds, setting in a range:
0.04 s .. 0.2 s with 0.01 s step
Activates/deactivates the function and display availability of the combined
parameters, see page 73 for details
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:
0.2 In .. 1In with 0.1 In step
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
Rev. B
): if the current I exceeds the I4 threshold the protection is
g g
Default
OFF
ON
t= k
0.2 In
0.4 s
90 % I4
OFF
0.04 s
OFF
0.2 In
0.1 s
SACE Tmax XT2 – XT4 | 40