Reset time setting
Inaccuracy: Reset time
0.010 … 10.000 s, step 0.005 s
±1.0 % or ±35 ms
Instant reset time and start-up reset
<50 ms
9.2.1.13. Over-/Under frequency (81O/81U) f>/<
Table. 9.2.1.13. - 274. Over-/Under frequency (81O/81U) technical data
Input signals
Sampling mode
Fixed
Tracking
Freq reference1
Freq reference2
Freq reference3
CT1IL1, CT2IL1, VT1U1, VT2U1
CT1IL2, CT2IL2, VT1U2, VT2U2
CT1IL3, CT2IL3, VT1U3, VT2U3
Pick-up
f> pick-up setting
f< pick-up setting
10.00…70.00 Hz, setting step 0.01 Hz
7.00…65.00 Hz, setting step 0.01 Hz
Inaccuracy (sampling mode)
-Fixed
-Tracking
±15 mHz (50 / 60 Hz xed frequency)
±20 mHz (U > 30 V secondary)
±20 mHz (I > 30 % of rated secondary)
Operation time
De nite time function operating time setting
0.00…1800.00 s, setting step 0.005 s
Inaccuracy
-De nite Time (Im/Iset ratio +/- 50mHz)
±1.5 % or ±50 ms (max step size 100mHz)
Instant operation time
Start time and instant operation time (trip):
(Im/Iset ratio +/- 50mHz) FIXED mode
(Im/Iset ratio +/- 50mHz) TRACKING mode
<70 ms (max step size 100mHz)
<3 cycles or <60 ms (max step size 100mHz)
Reset
Reset ratio
0.020 Hz
Instant reset time and start-up reset
(Im/Iset ratio +/- 50mHz) FIXED mode
(Im/Iset ratio +/- 50mHz) TRACKING mode
<110 ms (max step size 100mHz)
<3 cycles or <70 ms (max step size 100mHz)
Note!
Secondary voltage must be higher than 2 volts or current higher than 0.25 amperes (peak-to
peak) to measure frequency.
Frequency is measured in 2 seconds after a signal is received.
Fixed freq. mode: When xed mode is used, the system nominal frequency should be set to 50
or 60 Hz.
Tracked freq. mode: When tracked mode is used the system nominal frequency can be
anything between 7...75 Hz.
9.2.1.14. Rate-of-change-frequency (81R) df/dt>/<
Table. 9.2.1.14. - 275. Rate-of-change-frequency (81R) technical data
Input signals
Sampling mode
Fixed
Tracking
Freq reference1
Freq reference2
Freq reference3
CT1IL1, CT2IL1, VT1U1, VT2U1
CT1IL2, CT2IL2, VT1U2, VT2U2
CT1IL3, CT2IL3, VT1U3, VT2U3
AQ-T257
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
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