Pickup Logic Of The Entire Device - Siemens siprotec 7SD610 User Manual

2 Functions
1-pole dead time During a 1-pole dead time, the load current flowing in the two healthy phases forces a
current flow via earth which may cause undesired pickup. The developing zero se-
quence voltage may also prompt undesired responses of the protective functions.
The indications „1pole open L1" (No. 591), „1pole open L2" (No. 592) and
„1pole open L3" (No. 593) are additionally generated if the „Open Pole Detector"
detects that current and voltage are absent in one phase – however, it also detects
that no current is flowing in the other phases. In this case, one of the indications will
only be maintained while the condition is met. This enables a single-pole automatic
reclosure to be detected on an unloaded line.
Specially for applications with busbar side voltage transformers the indication „1pole
open Lx" is additionally transmitted if the phase-selective CB auxiliary contacts
clearly show a single-pole open circuit breaker, and the current of the affected phase
falls below the parameter 1130 PoleOpenCurrent.
Depending on the setting of parameter 1136 OpenPoleDetect., the Open Pole De-
tector evaluates all available measured values including the auxiliary contacts (default
setting w/ measurement) or it processes only the information from the auxiliary con-
tacts including the phase current values (setting Current AND CB). To disable the
Open Pole Detector, set parameter 1136 to OFF.

2.16.1.4 Pickup Logic of the Entire Device

Phase Segregated The fault detection logic combines the fault detection (pickup) signals of all protection
Fault Detection functions. In the case of those protection functions that allow for phase segregated
pickup, the pickup is output in a phase segregated manner. If a protection function
detects an earth fault, this is also output as a common device alarm. Thus, the alarms
„Relay PICKUP L1", „Relay PICKUP L2", „Relay PICKUP L3" and „Relay
PICKUP E" are available.
The above alarms can be allocated to LEDs or output relays. For the local display of
fault event messages and for the transmission of event messages to a personal com-
puter or a centralized control system, several protection functions provide the possi-
bility to display the faulted phase information in a single message, e.g. „Diff Flt.
L12E" for a differential protection pickup L1-L2-E.
General Pickup The pickup signals are combined with OR and lead to a general pickup of the device.
It is signalled with „Relay PICKUP". If no protective function of the device has picked
up any longer, „Relay PICKUP" disappears (indication „OFF").
General device pickup is a precondition for a series of internal and external functions
that occur subsequently. The following are among the internal functions controlled by
general device pickup:
• Opening of fault case: from general device pickup to general device dropout, all
• Initialization of fault storage: the storage and maintenance of fault values can also
• Generation of spontaneous indications: Certain fault indications can be displayed
• Start action time of automatic reclosure (if available and used).
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fault indications are entered in the trip log.
be made dependent on the occurrence of a trip command.
as spontaneous indications (see margin heading „Spontaneous Indications"). In ad-
dition, this indication can be made dependent on the general device trip.
7SD610 Manual
C53000-G1176-C145-4