Page 45 - MCCB-XT2-XT4

ABB | SACE Tmax XT

IU Protection Function
The protection trips if the current readings are unbalanced; the protection sends a TRIP command if the
t detected unbalance exceeds threshold I6 for longer than t6.
I6 IU The protection is automatically self-excluding in two cases:
• the measurement of at least one current exceeds 6 In
t6 • the maximum current value between all the phases is less than 0.25 In (in I Avg configuration) or
0.3 In (in I Max configuration)
To check and simulate the trip times in relation to all the parameters, please consult:
I
• summary table of the protections with the operating characteristics (page 75)
• the graph with trip curve (page 85)
Parameters
Parameter Description Default
Activates/deactivates the protection and its availability in the
Enable OFF
parameters menu
Activates/deactivates transmission of the open command: if disabled,
Trip Enable the alarm and exceedance of protection time are only managed as OFF
information
Allows the unbalance calculation mode to be selected:
• With respect to I max : % Sbil = 100 x (I max - I min ) / I max With
• With respect to: I : % Sbil = 100 x (max I ) / I
Algorithm Avg Avg Avg respect
NOTE:max I Avg : maximum deviation among the measured currents,
calculated by comparing each current with the mean value; to I max
I : mean value of the current readings
Avg
Establishes the unbalance value that trips the protection.
Threshold I6 Unbalance is given in percentage value within the range: 2% to 90% with 50 %
1% steps.
This is the trip time of the protection; the value is given in seconds and
Time t6 5 s
can be set within a range: 0.5 s to 60 s, in 0.5 s steps
Ekip M Touch
With Ekip M Touch, IU protection features the following differences compared to the other models:
• version set as With respect to I Avg , cannot be edited
• protection is inhibited if the rms value of at least one of the phase currents is less than 0.25 In.

Neutral Protection Function
Neutral protection characterizes protections L, S and I differently on the neutral phase by introducing a
different control factor from the other phases.
The protection is available with the 4P and 3P + N configuration; the configuration parameters can be
accessed via the Settings menu (page 29).
Parameters
Parameter Description Default
Enable Activates/deactivates the protection OFF
Defines the multiplicative factor applied to the trip thresholds and
curves of the protections for the current read on phase Ne:
Neutral • 50 %: lowest trip thresholds for the neutral current
threshold • 100 %: same trip thresholds for all phases 50 %
• 150 %: highest trip thresholds for the neutral current
• 200 %: highest trip thresholds for the neutral current

Limitations and additional functions
Ekip Touch rejects modification of thresholds I1 and InN in the absence of the following limitation: (I1 x
InN) ≤ Iu
• I1 is the threshold of L protection in amperes (example: In= 100 A and I1= 0.6 becomes I1= 60 A)
• InN is the neutral threshold expressed as multiplicative factor (example: InN= 200% becomes InN= 2)
• Iu is the size of the CB
WARNING! With 150% and 200% threshold; if the measured neutral current exceeds 16In,
the Trip unit resets the protection to 100% by itself

43 | © 2022 ABB | 1SDH002031A1002 - ECN000212994 Protections | 2 - Standard Protections