ABB Sace Emax 2 Installation, Operation And Maintenance Instructions For The Installer And The User page 36

S Protection
t
I2
t2
34 | © 2022 ABB | 1SDH000999R0002 - ECN000232533
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 39.
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 | 1 - Protections - Introduction