ABB SACE Tmax XT5 Operation And Maintenance Manual page 61

OF2 Protection
t
f18
OF2
t18
59 | © 2019 ABB | 1SDH002039A1002 - ECN000093027 - Rev. A
Function
OF2 protection functions in the same way as OF protection: the protection sends a TRIP command if the grid
frequency read by the unit exceeds threshold f18 for longer than t18.
It is independent of OF protection, thus thresholds and functions of the two protections can be programmed
so as to take advantage of different plant solutions (example: signaling with OF and open command with OF2
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.
To check and simulate the trip times in relation to all the parameters, please consult:
f
• summary table of the protections with the operating characteristics (page 80)
• the graph with trip curve (page 91)
Parameters
Parameter Description
Activates/deactivates the protection and its availability in the
Enable
parameters menu
Activates/deactivates transmission of the open command: if disabled,
the alarm and exceedance of protection time are only managed as
Trip Enable
information
Establishes the value that activates the protection.
The value is given as both absolute value (Hertz) and relative value (Fn)
Threshold f18
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 seconds and
Time t18
can be set within a range: 0.06 s to 300 s, in 0.01 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 75).
ABB | SACE Tmax XT
Default
OFF
OFF
1,1 Fn
3 s
Protections | 4 - Frequency protections