S Protection - ABB SACE Emax 2 Installation, Operation And Maintenance Instructions For The Installer And The User

S Protection

t
I2
t2
38 | © 2017 ABB | 1SDH000999R0002 - ECN000058721 - Rev. B
The S protection protects against the 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 read 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 modules Ekip T&P or Ekip Bluetooth and with the Ekip Connect software, it is possible to activate
the function Thermal Memory. See page 42.
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 43.
It defines the current value that if exceeded activates the protection (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 by the trip unit
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 protection trip unit | 2 - Protections