Table. 5.5.5. - 199. Pick-up characteristics setting
Name Range
Step
Default
Description
ILow
0.10 …
40.00xIn 0.01xIn 0.20xIn
Pick-up setting for low current detection. All measured currents must be below this
setting in order the CLPU signal shall be activated.
IHigh
0.10 …
40.00xIn 0.01xIn 1.20xIn
Pick-up setting for high current detection. Any measured current must exceed this
setting directly from the ILow condition in order CLPU signal shall be activated.
IOver
0.10 …
40.00xIn 0.01xIn 2.00xIn
Pick-up setting for over current detection. In case this setting is exceeded by any
measured current the CLPU signal shall be released immediately.
The pick-up activation of the function is not directly equal to start-signal generation of the function.
Start signal is allowed if blocking condition is not active.
Function blocking
In the blocking element the block signal is checked in the beginning of each program cycle. Blocking
signal is received from the blocking matrix for the function dedicated input. If the blocking signal is not
activated when the pick-up element activates, a START signal is generated and the function proceeds
to the time characteristics calculation.
If blocking signal is active when pick-up element activates a BLOCKED signal will be generated and the
function shall not process the situation further. If START function has been activated before blocking
signal it will reset and the release time characteristics are processed as in case of when pick-up signal
is reset.
From blocking of the function a HMI display event as well as time stamped blocking event with
information of the startup current values and fault type is issued.
Blocking signal can be tested also in the commissioning phase of the stage by software switch signal
when relay common and global testing mode is activated.
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
The operating timers’ behavior of the function can be set for activation and the cold load pick up
situation monitoring and release.
In the table below are presented the setting parameters for the function time characteristics.
Table. 5.5.5. - 200. Operating time characteristics setting parameters.
Name
Range
Step
Default
Description
Tset
0.000…
1800.000s 0.005s 10.000s
CLPU start timer, this setting de nes how long the ILow condition has to last before
CLPU is activated.
Tmax
0.000…
1800.000s 0.005s 30.000s
CLPU max timer, this setting de nes how long the starting condition can last and
the current is allowed to be over IHigh.
Tmin
0.000…
1800.000s 0.005s 0.040s
CLPU min timer, this setting de nes how long the starting condition last for
minimum time. In case if the start up sequence includes more than one inrush
situation this parameter may be used to prolong the CLPU time over the rst
inrush. Also this parameter operates as “reclaim” time for the CLPU function in
case the inrush current is not immediately initiated in the start-up sequence.
Few typical cases of CLPU situations are presented in the gures below.
AQ-F255
Instruction manual
Version: 2.00
243
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