Functions
2.4 Dynamic Cold Load Pickup
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008
125
2.4.2
Setting Notes
General
The dynamic cold load pickup function can only be enabled if address
117
Coldload Pickup
was set to
Enabled
during configuration of the protective functions. If not required, this function should be set to
Disabled
. The function can be turned
ON
or
OFF
under address
1701
Coldload Pickup
.
Depending on the condition that should initiate the cold load pickup function address
1702
Start Condition
is set to either
No Current
,
Breaker Contact
or to
79 ready
. Naturally, the option
Breaker Contact
can only be selected if the device receives information regarding the switching state of the circuit breaker via
at least one binary input. The option
79 ready
modifies dynamically the pickup thresholds of the directional
and non-directional time overcurrent protection when the automatic reclosing feature is ready. To initiate the
cold load pickup the automatic reclosing function provides the internal signal "79M Auto Reclosing ready". It is
always active when auto-reclosure is available, activated, unblocked and ready for a further cycle (see also
margin heading "Controlling Directional/Non-Directional Overcurrent Protection Elements via Cold Load
Pickup" in Section 2.14.6).
Time Delays
There are no specific procedures on how to set the time delays at addresses
1703
CB Open Time
,
1704
Active Time
and
1705
Stop Time
. These time delays must be based on the specific loading characteristics
of the equipment being protected, and should be set to allow for brief overloads associated with dynamic cold
load conditions.
Non-Directional 50/51 Elements (phases)
The dynamic pickup values and tripping times associated with the time overcurrent protection functions are set
at address block 18 for the phase currents:
The dynamic pickup and delay settings for the high-set elements are set at addresses
1801
50c-2 PICKUP
or
1808
50c-3 PICKUP
and
1802
50c-2 DELAY
or
1809
50c-3 DELAY
respectively; the dynamic pickup
and delay settings for the 67N-1 element are set at addresses
1803
50c-1 PICKUP
and
1804
50c-1 DELAY
respectively; and the pickup, time multiplier (for IEC curves or user-defined curves), and time dial (for ANSI
curves) settings for the 67N-TOC element are set at addresses
1805
51c PICKUP
,
1806
51c TIME DIAL
and
1807
51c TIME DIAL
respectively.
Non-Directional 50N/51N Elements (ground)
The dynamic pickup values and time delays associated with non-directional time overcurrent ground protection
are set at address block 19:
The dynamic pickup and delay settings for the high-set elements are set at addresses
1901
50Nc-2 PICKUP
or
1908
50Nc-3 PICKUP
and
1902
50Nc-2 DELAY
or
1909
50Nc-3 DELAY
respectively; the dynamic
pickup and delay settings for the 67N-1 element are set at addresses
1903
50Nc-1 PICKUP
and
1904
50Nc-
1 DELAY
respectively; and the pickup, time multiplier (for IEC curves or user-defined curves), and time dial (for
ANSI curves) settings for the 67N-TOC element are set at addresses
1905
51Nc PICKUP
,
1906
51Nc T-
DIAL
and
1907
51Nc T-DIAL
respectively.
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