Reset time setting
Inaccuracy: Reset time
0.010 … 10.000 s, step 0.005 s
±1.5 % or ±60 ms
Instant reset time and start-up reset
<55 ms
9.2.1.7. Harmonic overcurrent (50H/51H, 68) Ih>
Table. 9.2.1.7. - 285. Harmonic overcurrent (50H/51H, 68) technical data
Input signals
Input magnitudes
Phase current IL1/IL2/IL3 TRMS
Residual current I01 TRMS
Residual current I02 TRMS
Pick-up
Harmonic selection
2nd, 3rd, 4th, 5th, 7th, 9th, 11th, 13th, 15th, 17th or 19th
Used magnitude
Harmonic per unit xIn
Harmonic relative Ih/IL
Pick-up setting
0.05…2.00 x In, setting step 0.01 x In (xIn)
5.00…200.00 %, setting step 0.01 % (Ih/IL)
Inaccuracy
-Starting xIn
-Starting xIh/IL
<0.03 xIn (2nd, 3rd, 5th)
<0.03 xIn tolerance to Ih (2nd, 3rd, 5th)
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 >1.05)
±1.0 % or ±35 ms
IDMT operating time setting (ANSI / IEC)
0.02…1800.00 s, setting step 0.001 x parameter
IDMT setting parameters
k Time dial setting for IDMT
A IDMT Constant
B IDMT Constant
C IDMT Constant
0.01…25.00 step 0.01
0…250.0000 step 0.0001
0…5.0000 step 0.0001
0…250.0000 step 0.0001
Inaccuracy
-IDMT operating time
-IDMT minimum operating time; 20 ms
±1.5 % or ±20 ms
±20 ms
Instant operation time
Start time and instant operation time (trip):
(Im/Iset ratio >1.05)
<50 ms
Reset
Reset ratio
95 % of pick-up setting
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
Note!
Harmonics generally: Amplitude of harmonic content has to be least 0.02 x In when relative
(Ih/IL) mode is used.
Blocking: To achieve fast activation for blocking purpose with harmonic OC stage the harmonic
stage may activate if rapid load change or fault situation occur. Intentional activation lasts for
about 20 ms if harmonic component is not present. Harmonic stage stays active in case the
harmonic content is above the pick-up limit.
Tripping: When using harmonic OC –stage for tripping make sure that the operation time is set
to 20 ms (DT) or higher to avoid nuisance tripping due the above mentioned reason.
AQ-F255
Instruction manual
Version: 2.00
349
© Arcteq Relays Ltd