ABB REC650 - Signals; Settings; Monitored Data; Operation Principle

8.1.4 Signals
Table 135: SAPTUF Input signals
Name
Type Default Description
U3P GROUP
SIGNAL
- Three phase group signal for voltage inputs
BLOCK BOOLEAN 0 Block of function
Table 136: SAPTUF Output signals
Name Type Description
TRIP BOOLEAN General trip signal
START BOOLEAN General start signal
RESTORE BOOLEAN Restore signal for load restoring purposes
BLKDMAGN BOOLEAN Measurement blocked due to low voltage
amplitude
8.1.5 Settings
Table 137: SAPTUF Group settings (basic)
Name
Values (Range) Unit Step Default Description
Operation Off
On
- - Off Operation Off / On
StartFrequency 35.00 - 75.00 Hz 0.01 48.80 Frequency set value
tDelay 0.000 - 60.000 s 0.001 0.200 Operate time delay
tRestore 0.000 - 60.000 s 0.001 0.000 Restore time delay
RestoreFreq 45.00 - 65.00 Hz 0.01 49.90 Restore frequency if frequency is above
frequency value
8.1.6 Monitored data
Table 138: SAPTUF Monitored data
Name
Type Values (Range) Unit Description
FREQ REAL - Hz Measured frequency
8.1.7 Operation principle
The underfrequency protection (SAPTUF) function is used to detect low power
system frequency. If the frequency remains below the set value for a time period
greater than the set time delay the TRIP signal is issued. To avoid an unwanted trip due
to uncertain frequency measurement at low voltage magnitude, a voltage controlled
blocking of the function is available from the preprocessing function, that is, if the
Section 8 1MRK 511 287-UEN A
Frequency protection
180
Technical manual