ABB | SACE Emax 2
62 | © 2017 ABB | 1SDH001330R0002 - ECN000058721 Rev. A
Ekip Touch protection trip unit | 9 - Touch protections
L Protection
L
I1
t
t1
I
Path
Main page - Menus - Protections
Function
L protection protects against overloads
NOTE:
the protection is available and active for all the versions of the trip unit. You can disable
the protection by configuring the trip unit with Rating Plug L = Off.
When the activation threshold is exceeded, the protection trips in a time that decreases as the current read
increases.
Parameters
Here is a list of the available parameters:
Parameter
Description
Curve
It determines the dynamic of the curve and the calculation of the tripping time,
conforming to various reference standards:
• t = k / I
2
according to IEC 60947-2.
• IEC 60255-151 SI
• IEC 60255-151 VI
• IEC 60255-151 EI
• t = k / I
4
according to IEC 60255-151
Each function corresponds to a mathematical expression that allows the tripping time to
be calculated. The details of the expressions are provided in the table on page 73.
IMPORTANT: if from the calculation the tripping time turns out to be less
than 1 second, it is automatically limited to 1 second.
Threshold I1
The value I1 contributes in calculating the tripping time, and also defines the current
value that, if exceeded, activates the protection (with reference to the curve, it is the
part parallel to the y-axis).
It is represented both as an absolute value (Ampere) and as a relative value (In, nominal
value defined by the Rating Plug).
IMPORTANT: the protection is activated and starts timing for currents
between 1.05 and 1.2 of the I1 threshold set. Example (with I1 set = 400 A):
the protection is activated for currents read between 420 A and 480 A.
Time t1
The value T1 contributes to calculate the tripping time (with reference to the curve, T1
affects the entire curve shifting it along the vertical axis).
IMPORTANT:
The protection limits the tripping time to 1 second in two cases:
•
if, according to the calculation, the time is less than 1 second.
•
If the fault current is greater than 12 In.
I1 Prealarm
The prealarm of L allows notification that the measured current is near the activation
threshold of the protection.
The prealarm state is activated for currents higher than a threshold that can be set by
the user, and is deactivated in two cases:
• Current lower than the prealarm threshold.
• Current higher than the protection activation threshold.
A value within the 50 % ... 90 % range can be entered, with 1 % steps.
L protection has
Thermal Memory
Summary of Contents for SACE Emax E1.2
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