ABB Relion 650 Series Technical Manual page 143

1MRK 511 424-UEN B
Bay control REC650 2.2 IEC
Technical manual
The frequency on both sides of the circuit breaker is also measured. The
frequencies must not deviate from the rated frequency more than ±5Hz. The
frequency difference between the bus frequency and the line frequency is measured
and may not exceed the set value FreqDiff.
Two sets of settings for frequency difference and phase angle difference are
available and used for the manual closing and autoreclose functions respectively, as
required.
The inputs BLOCK and BLKSC are available for total block of the complete
SESRSYN function and selective block of the Synchrocheck function respectively.
Input TSTSC will allow testing of the function where the fulfilled conditions are
connected to a separate test output.
The outputs MANSYOK and AUTOSYOK are activated when the actual measured
conditions match the set conditions for the respective output. The output signal can
be delayed independently for MANSYOK and AUTOSYOK conditions.
A number of outputs are available as information about fulfilled checking
conditions. UOKSC shows that the voltages are high, UDIFFSC, FRDIFFA,
FRDIFFM, PHDIFFA, PHDIFFM shows when the voltage difference, frequency
difference and phase angle difference are out of limits.
Output INADVCLS, inadvertent circuit breaker closing, indicates that the circuit
breaker has been closed at wrong phase angle by mistake. The output is activated,
if the voltage conditions are fulfilled at the same time the phase angle difference
between bus and line is suddenly changed from being larger than 60 degrees to
smaller than 5 degrees.
Section 8
Control
137