ABB Relion 670 series, Technical Manual

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Simplified logic diagram for lockout functionality is shown in Figure 321 .
AND TRIP
OR
SETLKOUT
AND
RESET
AND
BLOCK
LOCKOUT
IEC12000020-2-en.vsdx
AutoLockout
IEC12000020 V2 EN-US
Figure 321: Trip Lockout logic
Alarm ripple detection
The rotor winding is provided with DC excitation current through the rectifier bridge and the
excitation transformer. In case a fault happens in the rectifier circuit, for example a short circuit or
broken diode/thyristor, the rotor system is endangered, due to asymmetry in the three phase
currents. This asymmetry will cause a ripple in the rotor DC current. This alarm method estimates
the ripple of the rotor DC current and if it exceed the preset level (parameter
AlmRippleLev) it will
start a timer (defined by parameter
tAlarmRipple). Once this timer has expired the signal ALRIPPLE
will be given.
The service value for the ripple level is provided. It is recommended to check the natural ripple of
the rotor DC current at site before the level for parameter AlmRippleLev is set. Note that this
ripple supervision shall only be used if the rotor DC current is used as measured quantity.
8.18.8 Technical data
GUID-98497E6C-7570-4160-926B-AEA3A24C42B6 v1
GUID-A1CB5B4F-768E-4B1B-937E-B91EC3EFA2CC v3
Table 332: GRPTTR (49R) technical data
Function Range or value Accuracy
Overcurrent start level for
overload protection
(105.0–900.0)% of IBase ±1.0% of I
r
at I ≤ I
r
±1.0% of I at I > I
r
Reset ratio, overcurrent >95% —
Start time, overcurrent at 0 to
2 x I
set
Min = 50 ms —
Max = 170 ms
Thermal time characteristic According to
IEEE Std C50.13–2005
±1.5% or ±200 ms whichever is greater
Minimum operate time for
thermal characteristic
(1.0–120.0) s ±1.5% or ±200 ms whichever is greater
Maximum operate time for
thermal characteristic
(100.0–2000.0) s ±1.5% or ±200 ms whichever is greater
Undercurrent start level (5.0–500.0)% of IBase ±1.0% of I
r
at I ≤ I
r
±1.0% of I at I > I
r
Table continues on next page
1MRK 502 066-UUS B Section 8
Current protection
597
Technical manual