Page 55 - MCCB-XT2-XT4

ABB | SACE Tmax XT

OF Protection Function
The protection sends a TRIP command if the grid frequency read by the unit exceeds threshold f13 for
t longer than t13.
f13 OF The protection excludes itself if the maximum value of the line-to-line voltage is less than 30 V.
To check and simulate the trip times in relation to all the parameters, please consult:
t13 • summary table of the protections with the operating characteristics (page 76)
• the graph with trip curve (page 88)
f 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
Trip Enable disabled, the alarm and exceedance of protection time are only OFF
managed as information
Establishes the value that activates the protection.
The value is given as both absolute value (Hertz) and relative
Threshold f13 1,1 Fn
value (Fn) and can be set within the range: 1 Fn to 1.1 Fn in 0.001
Fn steps
This is the trip time of the protection; the value is given in
Time t13 seconds and can be set within a range: 0.06 s to 300 s, in 0.01 s 3 s
steps

Limitations and additional functions
The block functions can also be accessed by means of the service connector (via Ekip Connect) or by
connection to the system bus (page 70).

UF2 Protection Function
UF2 protection functions in the same way as UF protection: the protection sends a TRIP command if the
t grid frequency read by the unit drops below threshold f17 for longer than t17.
UF2
f17 It is independent of UF protection, thus thresholds and functions of the two protections can be
programmed so as to take advantage of different plant solutions (example: signaling with UF and open
t17 command with UF2 or vice versa, or both for signaling or tripping).
The protection excludes itself if the maximum value of the line-to-line voltage is less than 30 V.
f To check and simulate the trip times in relation to all the parameters, please consult:
• summary table of the protections with the operating characteristics (page 75)
• the graph with trip curve (page 88)
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
Trip Enable disabled, the alarm and exceedance of protection time are only OFF
managed as information
Establishes the value that activates the protection.
The value is given as both absolute value (Hertz) and relative
Threshold f17 0,9 Fn
value (Fn) and can be set within the range: 0.9 Fn to 1 Fn in 0.001
Fn steps
This is the trip time of the protection; the value is given in
Time t17 seconds and can be set within a range: 0.06 s to 300 s, in 0.01 s 3 s
steps

Limitations and additional functions
The block functions can also be accessed by means of the service connector (via Ekip Connect) or by
connection to the system bus (page 70).

53 | © 2022 ABB | 1SDH002031A1002 - ECN000212994 Protections | 5 - Frequency protections