Page 38 - MCCB-XT2-XT4

ABB | SACE Tmax XT

L Protection Function
If the current of one or more phases exceeds threshold I1, the protection trips and, after a time established
t by the value read and by the parameter settings, transmits the TRIP command.
I1 L To check and simulate the trip times in relation to all the parameters, please consult:
• the summary table of the protections with the calculation formulas (page 75)
t1 • the graph with trip curve (from page 78)
Parameters
I NOTE: the limitations and default parameters of the Ekip M Touch Trip unit are different
from those of the other models. Details are given after the table

Parameter Description Default
Establishes curve dynamics and trip time calculation:
• t = k / I according to IEC 60947-2.
2
• IEC 60255-151 SI
Curve t = k/I 2
• IEC 60255-151 VI
• IEC 60255-151 EI
• t = k / I according to 60255-151
4
Establishes the value that activates the protection and
contributes towards calculating the trip time.
Threshold I1 1 In
The value is given as both absolute value (A) and relative value (In)
and can be set within the range: 0.4 In to 1 In, in 0.001 In steps
Contributes towards calculating the trip time.
The value is given in seconds and can be set within the range: 3 s
Time t1 12 s
.. 60 s (for curve t = k / I ) or 3 s .. 9 s (for the other curves), in 1 s
2
steps
Activates/deactivates the thermal memory function (page 67)
Thermal NOTE: the function is always ON with Ekip M Touch and OFF
memory
available with curve t = k / I for all the other trip unit models
2
Warns that the measured current is near to protection activation
threshold I1.
The value is given in percentage of threshold I1 and can be set
Prealarm I1 within the range: 50% I1 to 90% I1, in 1% steps. 90 % I1
NOTA: the prealarm condition deactivates in two cases:
• current lower than prealarm threshold I1
• current higher than threshold I1

Ekip M Touch
With Ekip M Touch, L protection features the following differences compared to the other models:
• Curve: non-editable; specific for Ekip M Touch (page 81)
• Time t1: non-editable; determined by the Trip class (page 63)
• Thermal memory: always enabled, functions according to standard IEC 60255-8; thermal memory
reset time is established by the Trip class (page 63)
• Different default parameters: t1 = 22 s (Class = 10E)
Limitations and additional functions
• threshold I1 must be lower than threshold I2 (if S protection is activated)
• the trip time of the protection is forcibly set at 0.5 s if the calculation results give a lower theoretical
value and/or if the current reading is more than 12 In
• with CB in UL standard configuration, the only available curve is t = k/I 2

36 | © 2022 ABB | 1SDH002031A1002 - ECN000212994 Protections | 2 - Standard Protections