S Protection - ABB SACE Emax E1.2 Operating Instructions For The Design Engineer

S Protection

t
I2
S
t2
21 | © 2017 ABB | 1SDH001330R0002 - ECN000058721 Rev. A
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).
Parameters
All the parameters that can be modified by the user affect the response curve, and related tripping times.
Parameter Description
I
Enable 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:
Type of curve
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).
Threshold I2
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).
Time t2
the parameter to 0.4 s.
With the modules Ekip T&P or Ekip Bluetooth and with the Ekip Connect software, it is possible to activate
the function Thermal Memory. See page 25.
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 26.
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.
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 by the trip unit
is 0.4 s. If a higher value is set, the trip unit signals the error and forces
ABB | SACE Emax 2
Ekip Dip protection trip unit | 2 - Protections