ABB SACE Tmax XT2 User Manual page 53

S2(V) Protection
Parameter
[2]
Threshold
Uh2
Threshold
Ks2
Time t21
Constraints, limitations, and additional functions
From the service connector (with Ekip Connect) or with system bus communication it is also
possible to access the block functions, see page70.
RV Protection Function
The protection is activated in case of loss of insulation (check residual voltage U0). If the voltage
U0 exceeds the threshold U22 for a time greater than t2, the protection sends the TRIP
command.
The protection is always available in 4P configuration.
To verify and simulate the trip times based on all the parameters, see:


Parameters
Parameter
Enable
Trip Enable
Threshold
U22
Time t22
Reset Time
Constraints, limitations, and additional functions
From the service connector (with Ekip Connect) or with system bus communication it is also
possible to access the block functions, see page70.
1SDH002031A1002 ECN000092998
Description
The parameter is shown with a Lin curve and helps to calculate the trip
threshold I21:
Mod Voltage read
< Uh2 (and  Ul2)
Lin
 Uh2
The value is expressed both as an absolute value (Volt) and as a relative
value (Un), settable in a range: 0.2 Un .. 1 Un with 0.01 Un step
Threshold I21 calculation constant.
The value is expressed as a percentage value of the threshold I21, which
is settable in a range: 0.1 I20 .. 1 I20 with 0.01 step
This is the trip time of the protection.
The value is expressed in seconds, which are settable in a range:
0.05 s ..30 s, with 0.01 s step
Protection summary table with the operating characteristics (page 79)
Chart with tripping curve (page 89)
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
Defines the value that activates the protection.
The value is expressed both as an absolute value (Volt) and as a
relative value (Un), settable in a range:
0.05 Un .. 0.5 Un with 0.001 Un step
This is the trip time of the protection; the value is expressed in
seconds, which are settable in a range:
0.05 s .. 120 s, with 0.01 s step
This is the alarm maintenance time after the protection has left the
alarm condition; this can be useful for keeping the timing active
even in the presence of temporary deactivation of the protection.
The value is expressed in seconds, settable in a range:
0 s .. 0.2 s, with 0.02 s step
Rev. B
Trip threshold
The threshold varies gradually (see
above)
I21
SACE Tmax XT2 – XT4 | 53
Default
1 Un
0.6 I20
0.1 s
Default
OFF
OFF
0.15 Un
15 s
0 s