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9.2.1.14 Overfrequency and underfrequency protection (f>/<; 81O/81U)
Table. 9.2.1.14 - 346. Technical data for the overfrequency and underfrequency function.
Input signals
Sampling mode
Fixed
Tracking
Frequency reference 1
Frequency reference 2
Frequency reference 3
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
±20 mHz (50/60 Hz fixed frequency)
±20 mHz (U > 30 V secondary)
±20 mHz (I > 30 % of rated secondary)
Operation time
Definite time function operating time setting
0.00…1800.00 s, setting step 0.005 s
Inaccuracy:
- Definite time (I
M
/I
SET
ratio +/- 50 mHz)
±1.5 % or ±50 ms (max. step size: 100 mHz)
Instant operation time
Start time and instant operation time (trip):
- I
M
/I
SET
ratio +/- 50 mHz (Fixed)
- I
M
/I
SET
ratio +/- 50 mHz (Tracking)
<70 ms (max. step size: 100 mHz)
<3 cycles or <60 ms (max. step size: 100 mHz)
Reset
Reset ratio
0.020 Hz
Instant reset time and start-up reset:
- I
M
/I
SET
ratio +/- 50 mHz (Fixed)
- I
M
/I
SET
ratio +/- 50 mHz (Tracking)
<110 ms (max. step size: 100 mHz)
<3 cycles or <70 ms (max. step size: 100 mHz)
No
Notte!
e!
• The secondary voltage must exceed 2 volts or the current must exceed 0.25 amperes (peak-
to peak) in order for the function to measure frequency.
• The frequency is measured two seconds after a signal is received.
• The fixed frequency mode: When the fixed mode is used, the system's nominal frequency
should be set to 50 or 60 Hz.
• The tracked frequency mode: When tracked mode is used, the system's nominal frequency
can be anything between 7...75 Hz.
9.2.1.15 Rate-of-change of frequency protection (df/dt>/<; 81R)
Table. 9.2.1.15 - 347. Technical data for the rate-of-change of frequency function.
Input signals
Sampling mode
Fixed
Tracking
Frequency reference 1
Frequency reference 2
Frequency reference 3
CT1IL1, CT2IL1, VT1U1, VT2U1
CT1IL2, CT2IL2, VT1U2, VT2U2
CT1IL3, CT2IL3, VT1U3, VT2U3
Pick-up
df/dt >/< pick-up setting
0.15…1.00 Hz/s, setting step 0.01 Hz
A
AQ
Q-C255
-C255
Instruction manual
Version: 2.06
404
© Arcteq Relays Ltd
IM00035