ABB SACE Tmax XT2 User Manual page 51

S(V) Protection
Parameter
[2]
Threshold Ul
Threshold Uh
Threshold
Ks
Time t20
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
This voltage determines the change of the trip threshold I20, with different
behaviour according to selective mode:
Mod Voltage read
< Ul
Scal
 Ul
< Ul
Lin
 Ul (and < Uh)
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
The parameter is shown with a Lin curve and helps to calculate the trip
threshold I21:
Mod Voltage read
< Uh (and  Ul)
Lin
 Uh
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 I20 calculation constant.
The value is expressed as a percentage value of the threshold I20,
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
Rev. B
Trip threshold
Ks x I20
I20
Ks x I20
��20 �� ( 1 − ���� ) �� (��
− ��ℎ)
������
��ℎ − ����
Trip threshold
The threshold varies gradually (see
above)
I20
SACE Tmax XT2 – XT4 | 51
Default
1 Un
+ ��20
1 Un
0.6 I20
0.1 s