ABB SACE Emax 2 Series Operating Instructions Manual page 27

S Protection
t
I2
t2
24 | © 2023 ABB | 1SDH001330R1002 - ECN000297030
S protection protects against selective short circuit.
NOTE: the protection is available for LSI and LSIG versions of the trip unit.
When the activation threshold is exceeded, the protection trips within a fixed or dynamic time (the time
decreases as the current reading increases).
S
Parameters
All the parameters that can be modified by the user affect the response curve, and related tripping times.
Parameter
I
Enable
Type of curve
Threshold I2
Time t2
With the module Ekip T&P and with the Ekip Connect software, it is possible to activate the function
Thermal Memory.
Description
By setting the threshold dip-switches to the Off position, the protection is
disabled.
It determines the dynamic of the curve and the tripping time, fixed or dynamic
according to the selection:
NOTE: calculation of the tripping time of the inverse time curve is
based on a mathematical expression. The details are provided in the table
on page#s#29.
It defines the current value that activates the protection when exceeded (with
reference to the curve, it is the part parallel to the y-axis).
IMPORTANT:
• The I2 threshold set must be higher than the I1 threshold. An
incorrect configuration returns an alarm signal.
• The delay is interrupted if the current drops below the activation
threshold.
The selected function determines the contribution of t2:
• Fixed time: t2 is the delay time between exceeding the I2 threshold and
sending the opening command.
• Dynamic time: t2 contributes in calculating the tripping time (with reference
to the curve, t2 affects the entire curve, shifting it as a whole along the vertical
axis).
IMPORTANT:
• The minimum tripping time of the protection is t2. If, according to
the calculation, the tripping time is less, it is automatically limited to
t2.
• For all the UL versions, the maximum time allowed is 0.4 s. If a
higher value is set, the trip unit signals the error and forces the parameter
to 0.4 s.
ABB | SACE Emax 2
Ekip Dip
2 - Protections - Introduction