Siemens 6MD85, Manual

Page: 298 / 1256

If, for the time set in the
Dropout delay curr.crit.
parameter, the maximum phase current falls below
the threshold value
Dropout threshold current
, the parameter set for the Cold-load pickup detection
function block is also deactivated. As a result, if the load current is very low, the action time
Dropout delay
curr.crit.
of the
>Activate cold-load
indication can be shortened.
Application and Setting Notes (Cold-Load Pickup Detection)
i
i
NOTE
The settings and indications described in this chapter are only available when using the optional Cold-load
pickup detection function block.
Parameter: Operating mode
•
Default setting
(_:101) Operating mode
=
I open
With the
Operating mode
parameter, you set the criteria with which the Closure-detection function block
operates.
Parameter Value Description
I open
When the Current-flow criterion function block detects a clearing open
condition, the decision is made for pickup. For this setting, make sure that
the
Current thresh. CB open
parameter is set lower than the
possible load current. If this is not the case, open is detected continuously
and each fault current that exceeds the
Current thresh. CB open
parameter is interpreted as closure.
CB and I open
Closure is detected if one of the following conditions is met:
•
Analysis of the circuit-breaker auxiliary contact detects a clearing open
condition in at least one phase.
•
The current-flow criterion detects a clearing open condition.
Parameter: Dropout threshold current
•
Default setting
(_:102) Dropout threshold current
=
1.00 A
With the
Dropout threshold current
parameter, you set the threshold at which the output signal
Cold-load pickup
is deactivated when the current in at least one phase falls below this threshold.
Parameter: Dropout delay current criterion
•
Default setting
(_:103) Dropout delay curr.crit.
=
600 s
With the
Dropout delay curr.crit.
parameter, you set the time for which the actual value must be
below the
Dropout threshold current
threshold so that the output signal
Cold-load pickup
can be
deactivated prematurely.
Parameter: Dropout delay CB closed
•
Default setting
(_:104) Dropout delay CB closed
=
3600 s
With the
Dropout delay CB closed
parameter, you set the action time for the dynamic parameter set
switching in the event of cold-load pickup detection.
Parameter:
Min. CB open time
•
Default setting
(_:105) Min. CB-open time
=
3600 s
With the
Min. CB-open time
parameter, you set the time after which the dynamic parameter set is acti-
vated in the event of cold-load pickup when the line is opened.
5.8.10
Function-Group Types
5.8 Process Monitor
298 SIPROTEC 5, High-Voltage Bay Controller, Manual
C53000-G5040-C015-9, Edition 11.2017