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User settable variables are binary signals from the system. Blocking signal needs to reach the IED
minimum of 5 ms before the set operating delay has passedfor blocking to be active in time.
Operating time characteristics for trip and reset
The operating timers’ behavior of the function can be set for trip signal and also for the release of the
function in case the pick-up element is reset before the trip time has been reached. There are three
basic operating modes available for the function. Instant operation gives the trip signal with no
additional time delay simultaneously with start signal. De nite time operation (DT) will give trip signal
with user given time delay regardless of the measured voltage as long as the voltage is below the Uset
value and thus pick-up element is active (independent time characteristics). Inverse de nite minimum
time (IDMT) will give the trip signal in time which is in relation of the set pick-up voltage Uset and
measured voltage Um (dependent time characteristics).
Where:
k = Time dial setting
Um = Measured voltage
Us = Pick-up setting
a = IDMT Multiplier setting
In the following table are presented the setting parameters for the function time characteristics.
Table. 5.4.12. - 120. Operating time characteristics setting parameters.
Name
Range
Step
Default
Description
Delay Type
DT
IDMT
-
DT
Selection of the delay type time counter. Selection possibilities are dependent
(IDMT, Inverse De nite Minimum Time) and independent (DT, De nite Time)
characteristics.
De nite
operating
time delay
0.000…
1800.000s 0.005s 0.040s
De nite time operating delay. Setting is active and visible when Delay Type is
selected to DT.
When set to 0.000 s the stage operates as instant (PIOC, 50) stage without
added delay. When the parameter is set to 0.005 – 1800 s the stage operates
as independent delayed (PTOC, 51).
Time dial
setting k
0.01…
60.00s
0.01s
0.05s
Setting is active and visible when Delay Type is selected to IDMT.
Time dial / multiplier setting for IDMT characteristics.
IDMT
Multiplier
0.01…
25.00s
0.01s
1.00
Setting is active and visible when Delay Type is selected to IDMT.
IDMT time multiplier in the Um/Uset power.
Table. 5.4.12. - 121. Reset time characteristics setting parameters.
Name
Range
Step
Default
Description
Release Time
delay
0.000…
150.000s 0.005s 0.06s
Resetting time. Time allowed in between of pick-ups if the pick-up has not
lead into trip operation. During this time the start signal is held on for the
timers if delayed pick-up release is active.
Delayed Pick-
up release
No
Yes
-
Yes
Resetting characteristics selection either time delayed or instant after pick-
up element is released. If activated the start signal is reset after set release
time delay.
AQ-F255
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
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