Page 46 - MCCB-XT5

P. 46

ABB | SACE Tmax XT

S2 Protection Function
S2 protection functions in the same way as S protection: if the current of one or more phases exceeds
t threshold I5 for longer than time t5, the protection activates and sends a TRIP command.
I5 S2
NOTE: unlike S protection, S2 protection only has one fixed time trip curve and has no
thermal memory
t5 It is independent of S protection, thus thresholds and functions of the two protections can be programmed
so as to take advantage of different plant solutions (example: signaling with S and open command with
I S2 or vice versa, or both S and S2 for signaling or tripping).
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 81)
• the graph with trip curve (page 88)
Parameter Description Default
Activates/deactivates the protection and its availability in the
Enable OFF
parameters menu.
Activates/deactivates transmission of the open command. if
Trip Enable disabled, the alarm and exceedance of protection time are only ON
managed as information.
Establishes the value that activates the protection and
contributes towards calculating the trip time.
Threshold I5 2 In
The value is given as both absolute value (A) and relative value (In)
and can be set within the range: 0.6 In to 10 In, in 0.1 In steps
This is the trip time of the protection.
Time t5 The value is given in seconds and can be set within the range: 0,05 s
0.05 s to 0.8 s, in 0.01 s steps
Activates/deactivates the function and selectivity time availability
on the display (page 73)
NOTE: if at least two of the selectivity S, S2, I, 2I and MCR
ZoneSelectivity OFF
are enabled, the input and output are shared with the OR
function; it is sufficient that even a selectivity is activated to
stimulate inputs and outputs
This is the trip time of the protection with the zone selectivity
function activated and selectivity input not present (page 73)
Selectivity time 0,04 s
The value is given in seconds and can be set within the range:
0.04 s to 0.2 s, in 0.01 s steps
Activates/deactivates the function and availability of the
StartUp enable OFF
associated parameters on the display (page 76)
Protection threshold valid during Startup time, in the conditions
StartUp in which the function is activated (page 76) 2 In
Threshold The value is given as both absolute value (A) and relative value (In)
and can be set within the range: 0.6 In to 10 In, in 0.1 In steps
This is the time for which the StartUp threshold remains
activated, as calculated from the moment the activation
StartUp Time Threshold is exceeded (page 76) 0.1 s
The value is given in seconds and can be set within the range: 0.1
s to 30 s, in 0.01 s steps

Limitations and additional functions
• threshold I5 must be higher than threshold I1 (if S2 protection is activated)
• the block functions and type of selectivity can also be accessed by means of the service connector
(via Ekip Connect) or communication via system bus (page 75)
• with CB in UL standard configuration, the maximum value of t5 is 400 ms

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